It's been four months since Pauline Levi Pierce slept in a bed. On I most nights -- and days -- she curls her frail body in a grease-caked raincoat and sleeps on the steps of the Luther Place Memorial Church near the prostitutes and harsh lights of Washington's 14th Street strip.

Pierce, 40, is a Washington street person, a member of the rag-tag army of homeless drifters who wander the streets, picking through trash barrels, dozing on park benches, clutching their tattered bags and bundles.

Many are disoriented, some alienated, refusing official offers of food and shelter. Others, like Pauline Pierce, do not quite fit into the bureaucratic and legal mold for institutionalization: She is not a danger to herself or others and thus cannot be forcibly removed from the street and hospitalized.

So Pierce drifts. A Navy veteran and divorced mother of five children, she sat in a downtown eatery the other day, scratching incessantly and talking about the life of a street person in Washington. At one moment, her mind seemed as clear as the autumn sunshine outside. A moment later, with the same sincere look in her green eyes, she calmly described a Nazi plot to take over the world in 1981. She says she has known of the plot since World War II. With winter now approaching, concern for the street people among charity institutions and churches that attempt to shelter them rises with the drop in temperatures. The Interfaith Conference of Metropolitan Washington estimates there are 1,000 to 3,800 homeless persons in Washington and the numbers are growing.

"There's nothing the mental health centers can do about such persons," said Conrad Hicks, of the Department of Human Services mental health branch. "A citizen has rights including that one cannot commit him if he is not a danger to himself or others." A person can be dangerous to himself "because he is not looking out for his own health, but that is a gray area. They may be committing slow suicide, but they are still lucid," Hicks said.

"It's heartbreaking. It's like saying no to the sickest of the sick," said the Rev. John Steinbruck of Luther Place Memorial Church.

"Women come here imagining they are pursued by the CIA, the KGB . . . ," said Steinbruck, who opens his church for five or six months each fall and winter to let homeless women sleep on the carpeted conference room floor.

"I hate to be out here. It's uncomfortable," Pauline Pierce declared with rare emotion. She said she has been harassed by men, beaten up by women and robbed several times since she forfeited her place in a women's shelter by refusing medical care and treatment for lice, which she denies having. She believes her clothing and personal papers have been stolen from one of the women's shelters where she left them.

Pierce said she came here on a Greyhound bus in September 1980 from Council Bluffs, Iowa, where she had lost a two-year court battle to regain custody of her children, ages 5 to 15. She had been granted custody by Florida courts, but her former husband took them to Iowa when the youngest was 7 months old, and persuaded the state courts there that she was incompetent to care for them, according to Sister Rosa of the Carmelite Sisters of Charity at 5th Street and G Place NW, where Pierce has been sheltered in the past.

Pierce said she came to Washington to look for a job, to collect her military savings and to run for president.

Daughter of a New York seamstress and a plumbing company clerk, Pierce was for seven years a smartly uniformed Navy petty officer, honorably discharged in August 1965. She was married for 12 years to a Naval officer she met in Italy, had five children by him and for a time was an Arlington housewife before her divorce and the dissolution of her conventional life.

Now, she sits in the grimy diner, gnawing a bacon-and-egg sandwich with brownish, chipped teeth, her hair in dirty, uncombed coils.

"I don't actually get hungry. I just get so weak I can hardly move," said Pierce, who eats once a day, "when I feel like it," at a soup kitchen near the bus station.

"The Carmelite Sisters keep trying to put me in the hospital. They say I need mental care. I don't know why," Pierce protested.

"That's a very sad story. Pauline is very intelligent," said Sister Rosa. She said Pierce's mother sends money, clothes and letters but is unable to persuade her, and unwilling to force her, to go to a hospital.

At the urging of Steinbruck's wife, Erna, a coordinator at Mount Vernon Day Center for Women, city mental health officer Minnie Bingham evaluated Pierce and found insufficient cause to commit her involuntarily.

"I did not see where she was overtly psychotic," said Bingham. "We have to be very careful about patients' rights."

Bingham said she will go back to review Pierce's situation on the streets "before it gets too cold."

Pierce, meanwhile, has her own mission: "I need a place to stay and my children and my money. Then I can take care of myself quite well." And her reality? "I'm mainly just trying to stay alive right now," she says.