The autumn afternoon is radiant, and life overflows at Casa Oscar Romero, as it must in a four-room house where 205 people live.

This white-walled sanctuary at the corner of Wentz and Bowie streets is an amazing half-acre of Central America just inside Texas along the lower Rio Grande border. The refugees here come mostly from villages in El Salvador and Nicaragua. They fled poor lands whose separate wars are treated very differently by Americans who see them through the prism of politics. From this house, the perspective is violence, poverty and survival, and the two wars look much the same.

Casa Romero stands in quiet defiance of U.S. policy toward both Central America and its refugees. Once an activist outpost of the Sanctuary Movement, a network of church workers committed to transporting and housing Central Americans who have entered the country illegally, it has settled solely into sheltering them -- Nicaraguans, whose government the United States opposes, equally with Salvadorans, whose government the United States supports.

Record numbers of Central Americans entered the United States illegally this summer and fall, and record numbers were apprehended along one of the busiest crossings in the region, between Rio Grande City on the west and Brownsville on the east, in the part of Texas known as The Valley. Casa Romero has been stretched beyond its capacity. The mayor of San Benito says its residents must move because they are too many. But Sister Ninfa Garza keeps the roof over their heads and says that when she looks around, she sees the beauty of life itself.

Twenty young men play soccer in the large front field, their ball occasionally clanging against the tin roof of the front porch, built last summer in the style of a roadside fruit stand. In the porch's shade, young girls read comics and practice their writing. Mothers rest in old stuffed sofas and fathers lean against the wooden pillars, talking in low voices about how they might reach relatives in Houston, Los Angeles and Washington.

Little boys play checkers with sets devised from jigsaw puzzle pieces. They chase each other around a shopping cart full of potatoes, past the pickup truck from which workmen are unloading a new freezer bought by Sister Garza's mother, around the telephone booth, the basketball hoop and the Dr. Pepper soft-drink machine. A five-year-old steals the ball from the soccer players. They plead with him. He retreats. Nearby, teenagers gather around a guitarist strumming the simple, joyous chords of "La Bamba." Inside, three women prepare supper. Beans and rice simmer in enormous kettles on the gas stove. It is not bedtime, yet some men sleep. The two bunkrooms cannot accommodate everyone at once.

There are people everywhere, too many people, and in recent months more have been coming than going. A year ago, the house was considered overcrowded if it slept 30. Now, that many Central Americans arrive in one day. "They keep coming, more of them, more of them with women and children," said Sister Garza, who runs the house for the Catholic Diocese of Brownsville. "They keep coming because there is a need."

Many of Casa Romero's residents are Central Americans who crossed the river without getting caught and are making this their first stop along the underground railroad set up by the Sanctuary Movement. But the population also includes, in almost equal numbers, illegal immigrants who were caught by the Border Patrol and freed on bond but are under orders to stay in the Rio Grande Valley until their requests for political asylum are decided.

The unending procession is recorded in yellow spiral notebooks kept in the office trailer 30 yards from the house. They show the name, homeland and date of arrival of every person who has slept here. The current notebook began Sept. 10 with the 6,030th person to pass through since they began keeping track two years ago. By Oct. 24, the number had reached 6,789 with the arrival of Miguel Pimental, 21, and Jose Mendez, 36, two surveyors who left Guatemala because they could not find work. They heard about Casa Romero on the highway outside Matamoros, Mendez said. "They told us there was a place where we could stay and rest, away from 'La Migra,' " their name for the U.S. Immigration and Naturalization Service.

Among the 759 refugees who had entered Casa Romero since September, about 40 were from Guatemala, fewer from Honduras and Costa Rica. The rest were about evenly split between Nicaragua and El Salvador. The refugees used to be predominantly Salvadoran, with Guatemalans second. But the balance seems to be shifting. There have been more days like Oct. 22, when 17 Nicaraguans, six Salvadorans and one Colombian signed in.

Despite the cultural and ideological differences the Salvadorans and Nicaraguans bring to Casa Romero, they coexist with as much serenity as the average family. They are bonded by religion, circumstance and Sister Garza.

On Oct. 1, a baby boy was born in the trailer, the first ever at Casa Romero. The infant's mother was Flor Aguiluz, 25, a Nicaraguan who said she had fled her homeland after the Sandinista army drafted her 14-year-old nephew. They came for him in the middle of the night, she said, and it scared her, so she left for America on June 30 with three cousins. They took a bus 1,700 miles through Mexico to the border city of Matamoros and on July 19 crossed the Rio Grande "mojado," which means wet. A priest in Brownsville directed her to Casa Romero, where she has been ever since.

Flor Aguiluz said politics means nothing to her. "The only thing I care about is peace in my country." Yet she has given her child a very special name with some political significance. He is Oscar Aguiluz, in honor of Casa Oscar Romero and the Roman Catholic archbishop killed in 1980 during a mass for his country's poor. His country was not Nicaragua but El Salvador, and he has become a martyr to the Salvadoran rebels.

The little boy wears a "Mets Rookie of the Year" t-shirt and is beloved by everyone at the house. They call him Oscarito and ask after him every day. When he was baptized a few Saturdays ago, they celebrated. He is a unifying symbol of hope.

There are disputes among the residents of Casa Romero but few that Sister Garza can't mediate by taking the antagonists for a walk around the front field. What she cannot control is how differently Americans treat the Nicaraguans and Salvadorans.

The main legal group for Central Americans in this part of the Rio Grande Valley is Proyecto Libertad, a nonprofit office of lawyers and paralegals based in nearby Harlingen. Proyecto Libertad helps Salvadorans and Guatemalans apply for political asylum and fight deportation. Its lawyers maintain that the refugees fled their countries' repression and violence. The Reagan administration, which has supported the Salvadoran and Guatemalan governments, says they are here for economic reasons. Nationwide, less than 3 percent of them have been granted asylum. None has won it in the Rio Grande Valley.

The lawyers at Proyecto Libertad charge $250 per case but only if the client can pay. They are driven by their belief in the cause of the Salvadoran and Guatemalan refugees, and the recent surge of Nicaraguans fleeing the Sandinista government is awkward for them: many in Proyecto Libertad are sympathetic to the Sandinista government. They are not so eager to help the Nicaraguan refugees. In explaining why, they sound somewhat like U.S. officials discussing Salvadorans.

"We've done a few Nicaraguan cases, but not many," said Proyecto Libertad lawyer Jeff Larsen. "We prefer not to. We find that most Nicaraguans are really here because of the economic situation. A lot of people in this office would be upset taking their cases. We know El Salvador. We know every province there and what is happening. We don't know Nicaragua the same way. This may sound naive, but I believe that Nicaraguans can depend on their government to protect them from human rights violations. Salvadorans don't feel that way."

Larsen said Casa Romero has turned away from its political roots. The house was once at the forefront of the Sanctuary Movement, whose leaders challenged U.S. immigration policy at trials that foreshadowed the current high-profile prosecution in Tucson of 11 movement workers. Jack Elder, a former director of Casa Romero, was convicted last year of conspiring to transport illegal aliens and served a 150-day sentence at a San Antonio halfway house. His successor, Lorry Thomas, was caught trying to smuggle a refugee past a Border Patrol checkpoint. She is serving a two-year prison term.

When Sister Garza took over last May, Bishop John J. Fitzpatrick directed her to refrain from political activism and concentrate on taking care of tired, hungry refugees. The Border Patrol has had no confrontations with Casa Romero since then and, according to regional Deputy Chief J.L. Hicks, there are no plans to raid the house. "There's no need to set up a media event for them," Hicks said. "You know, the gestapo Border Patrol comes in. As long as they don't move beyond what they're doing now, we will leave them alone."

"It's really changed over there," said Proyecto Libertad's Larsen. "The church has backed down, and the place is run by the Nicaraguans." He recalled going to the house a few weeks ago to work on some Salvadoran cases and being overrun by Nicaraguans pleading for help.

Sister Garza remembered that visit, too. "The lawyers made it so clear that they would help some and not others that it made it difficult for us. The Nicaraguans would ask: 'What is wrong with us? Why are we different?'

"I had to hold a meeting to talk about it. We got everyone together on the porch, and I said: 'Here we open the door for anyone in need. It doesn't matter where you are from. The only questions we ask are whether you are hungry and whether you need a place to rest. I'm trying to build a community."

The rules in Sister Garza's community are simple. No drinking. Respect for others. Cleanliness. Every two weeks, the people of the house elect new leaders to enforce the rules. A daily schedule is posted on the bulletin board on the front porch, next to a picture of Pope John Paul II. The residents, not Sister Garza, enforce the rules and make sure the schedule is followed, from awakening at 7 a.m. to religious stories and songs at 9:30 p.m. There are committees for every function. As people leave -- as they move on to Washington, Miami and Houston, or as they are deported back to Managua or San Salvador -- new committees are formed.

Casa Romero is home to dozens of school-age children. The U.S. Supreme Court has ruled that public schools must educate illegal immigrants if they have established residence in a district. But the youngsters of this house do not stay long enough to go to school. What they learn they are taught by their elders and by volunteers such as Cheryl Opgaard, a second-grade teacher in the San Benito public schools who comes in the late afternoon to teach English.

She walks across the field carrying poster board, pencils and a sheaf of paper and shouts, "English class! English class!" as she moves into the main room. She is followed by a gaggle of little children who settle on the wooden floor in front of her. A few dozen older children join in.

The first 30 minutes are taken up with one exchange.

"What is your name?"

"My name is . . . . "

They say it together, then one at a time. Opgaard exaggerates her facial motions, especially the way she presses her lips for the "m" in "name." The children have a hard time with the "m." They go over it time and again. Then she has them say their names. Herbert is first. He responds correctly. Then comes Carlos. "My name is . . . . " He says that part perfectly, and he smiles. But then he forgets his name: "My name is, um. My name is . . . Herbert!"

The next half-hour is spent on the exchange: "Where are you from?" "I am from . . . . "

Opgaard has one child ask the question and the next one answer it, going around the room. She begins.

"Where are you from?" she asks Carlos.

"I am from El Salvador."

"Where are you from?" Carlos asks Juan.

"I am from Nicaragua."

Sister Garza returns from the bank, where she has received a check that will serve as bond for a Salvadoran family caught by the Border Patrol. They will be allowed to move on to Houston and live with relatives there while their asylum request is considered. Sister Garza loves her job and the people she serves. "They are good people, very respectful people," she says, and when she moves among them, she says, she feels closer to God than she ever has within a church.

On July 31, her birthday, the nearly 300 refugees at Casa Romero held a celebration. Benches and chairs were carried out to the front field and placed in a large circle. Sister Garza sat in the middle as one family after another sang special songs to her of their country and their village.

Two nights each week the people gather in the field: Salvadorans, Nicaraguans, Hondurans, Guatemalans, mothers, fathers, teenagers, children, thousands of miles from home. Sister Ninfa Garza leads them in prayer. They look up at the stars and say: "This is a beautiful sky. It is our sky. There are no boundaries in the sky."

Next: The detention center