When Radio Mundo broke the news to 100,000 Spanish-speaking listeners Tuesday that the House had approved a bill that would halt deportation of illegal Salvadorans and Nicaraguans, the Wheaton station's phones started ringing.

"It is true that we are able to stay for two years more, no?" was the typical question, radio news director Rafael Ortega said.

All around the Washington area yesterday, Salvadorans, who number 150,000 to 200,000, celebrated the spreading news of the 237-to-181 House vote.

Even though the Reagan administration has vowed to veto the bill, Arlene Gillespie, director of the D.C. Office of Latino Affairs, said, "It's the best news we've heard in years."

The House measure would ban deportations for about two years while the General Accounting Office studies the conditions in Nicaragua and El Salvador and the danger of deporting illegal immigrants back to those countries stricken by war. During that time, Nicaraguans and Salvadorans would be allowed to work here.

The Senate Judiciary Committee has approved a similar bill. A spokesman for Sen. Dennis DeConcini (D-Ariz.), a sponsor of the measure, said he believes the Senate has enough votes to pass it, though there do not appear to be enough congressional votes to override a veto.

The Salvadoran community responded to the news of the bill's House passage with cautious joy.

"We're thrilled," said Sylvia Rosales, executive director of Carecen, a nonprofit group offering legal help to the Hispanic community. "But we know there are people in the administration with very stubborn views on Central America . . . . I think we have a 50-50 chance."

"It would be terrible if these people were deported," said Virginia Maldonado, a Salvadoran shopkeeper in Adams-Morgan. "Every family has already lost a son or a brother in the war. Mothers are selling their homes to send their son here to keep him safe."

Maldonado believes Reagan can be persuaded to see things her way. "Mr. Reagan must know that the Salvadoran people work hard," she said. "They take the jobs American people don't want to do."

Gillespie said she believes 90 percent of the illegal Salvadorans in the Washington area will register with immigration officials if the measure becomes law.

Since the 1986 immigration reform laws barred employers from hiring undocumented workers, requiring fines of as much as $10,000 for each illegal worker, it has been increasingly difficult for the thousands of Salvadorans here to earn a living.

Duke Austin, Immigration and Naturalization Service spokesman, said the administration believes the temporary deportation ban would send "an unfortunate signal. It encourages a lot more people to come illegally."

Austin said there are other ways to ensure that Salvadorans and Nicaraguans are not deported if they face danger at home.

He said they can apply for political asylum, and if they lived here before 1982, under the new immigration laws they can apply for amnesty. Most come here for jobs and not to escape political problems, he said.

However, according to congressional figures, while most Nicaraguans who apply for political asylum are granted it, only 3 percent of Salvadoran applicants receive it.

In addition, most of the Salvadorans in the Washington area have arrived since 1982.

An illegal Salvadoran, who learned of the House measure yesterday when his wife called him, said he hurried out to get a newspaper to read more about it.

"I am happy," he said. "But I fear there will be some political maneuvering before it's over."