HE'S A YOUNG husband keen to adopt a baby. She's the officious salesclerk at a discount adoption agency, pusing a special "1-cent sale" that offers an extra infant for a penny.

She's "Helen Graves, the Other Woman" in a parody of those "50s movie tearjerkers that starred Susan Hayward or Jane Wyman or Lana Turner. He's the married smoothie who jilts her (until, melodramatic eons later, she has graduated from a home-study course in plastic surgery and he - his face mauled in an auto accident - turns up on her operating table).

He's a lonely young single. She's an inflatable female companion, who patiently listens to his problems (until she springs a leak).

Jan Frederick Shiffman and Dana Vance are these and other assorted mixed nuts in "Grownups," a crackerjack series of comic sketches (written, with some help from the stars, by Tim Grundmann) that has been packing weekend crowds into the New Playwrights' Theatre on Church Street NW and will soon move along to Georgetown's Cellar Door and New York's Reno Sweeney's.

The boisterous Vance, mistress of a million uncouth accents, and the quieter but shiftier Shiffman, who always seems ready to disappear behind a tree the way very tall and lanky cartoon characters do, are two of the best young actors in Washington. This means they will be leaving Washington as soon as they can arrange it: In the nation's capital, career opportunities for actors are only a shade more plentiful than they are for big-game hunters.

"It's not like we have some kind of raging vendetta against Washington," says Shiffman. "But we want to work."

An actor who wants to work is not unusual. What makes Vance and Shiffman downright peculiar, however, is their determination to avoid work they regard, unabashedly, as beneath them.

"We don't want to carry spears or do dinner-theater versions of "Oklahoma" or "Brigadoon," " says Shiffman, who is only 25 despite a beard and moustache that would look at home on a turn-of-the-century yacht-club gigolo.

"For me to be a spear-carrier would be foolish," says Vance, who is 27, although she plays women from adolescence to dotage, dipping into her vast and varied wig collection. "Let's face it, I'm a dynamic lady," she says. "I'd look out of place in the chorus."

Vance, Shiffman and Grundmann (who not only wrote "Grownups" but accompanies it on the piano), met at West Virginia University about five years ago. Grundmann and Vance had come there to study the piano and Shiffman to major in Spanish. All three left with a large interest in the theater.

Vance grew up in the steel town of Weirton, W. Va., where her father (who had changed the family name from Vujonovic to Vance effective with her birth) ran a dry cleaner's. Her parents crammed her childhood full of voice, piano and tap-dancing lessons. But when Vance began to think about becoming an actress or a dancer, her mother asked her, "Why would you want to be one of those things?"

Her parents did want her to become a pianist, since her sister was an opera singer and "they figured I'd be able to accompany her on the piano, which was very nice for them but not particularly nice for me," she says.

Her folks eventually came around, she is careful to add. "My parents have seen everything I've ever done."

Shiffman's equally non-show-biz origins were in Pittsburgh, where his father works for U.S. Steel. He quit college after two years and went back home to work in a bank, then moved to Washington, as Grundmann did, because Vance, who had come here the day after she graduated, wanted company.

"I just relocated because it was something to do," says Shiffman.

With four other friends, they formed "Poor Richard's Players," a nightclub act with a patriotic focus. "It was the year of the Bicentennial and we were moving with the flow," explains Shiffman apologetically.

Although that group and its smaller successor, "Red Shoes Walkin" " (restaurant jargon for "french fries with ketchup to go") eventually made appearances at the Cellar Door, the Warner (as an opener for Eartha Kitt), Waay Off Broadway (for Barbara Cook) and the Kennedy Center (as part of a human rights benefit), it was never very gainful employment. Money had to come from elsewhere. And while Vance and Shiffman may follow a set of strict rules about where they will and won't appear as actors, they have both worked at a wide and highly unprestigious range of other employment.

Vance has been a waitress at the Cafe de Paris, the Guards, the Dubliner and the Gandy Dancer. Shiffman, once also a waiter at the Cafe de Paris, has tended bar at the Here and Now, been a D.C. National Bank teller, an accountant for Alonzo Vogue Boutique and, most recently, an advertising credit-checker for The Washington Post.

It was Grundmann's discovery of the New Playwrights' Theatre and New Playwrights' discovery of Grundmann that led to a series of oddball musicals in which Vance and Shiffman have taken prominent part. All have been among New Playwrights' most successful productions, and the second of the series, "Bride of Sirocco," was moved to the West End Theater (before its conversion to a movie house) for an extended run.

Shiffman and Vance make no bones about the fact that they would rather be stars in this small arena than bit-players on a bigger stage (with, perhaps, more accomplished directors, writers and fellow actors). "My confidence comes out of the fact that I've had good roles in all of Timmy's shows," says Shiffman.

And neither has felt the need to study acting. Pure experince is the best teacher, they both agree.

"I don't need to study acting," says Vance. "You're an actor or you're not." She does study humanity, however. "If I could, I'd get a folding chair and put it out on M Street or 19th and just watch," she says.

Vance has done radio commercials for Montgomery Mall and Rock Creek sparkling water, but she's not sure they repaid the ordeal of criss-crossing the city to drop her photos, resumes and voice tapes off at casting and advertising agencies, then phoning the key people to death.

When she was called for a live audition by one agency, says Vance, the head of the agency told her, "You know, you're marvelous. I'm going to get you work."

"I have subsequently called him 25 times," says Vance, "and he hasn't called me back one."

It also ticks her off that a series of starring parts (and favorable reviews) at the New Playwrights' Theatre and other local theaters and clubs seems to make no impression on the people who produce radio and TV commercials here. Instead, she says, they rely on a small coterie of actors who have done commercials for years.

"They'll say, "Well, we'll get so-and-so because we've got to do this one fast and we need someone who'll show up on time," " says Shiffman. "Well, there are other people who would show up on time."

Shiffman's search for commercials never advanced beyond his first visit to an advertising agency, where an executive standing in the same office with him brusquely instructed an assistant to "tell him we're not seeing anybody," and otherwise failed to acknowledge Shiffman's presence.

"It's not like you expect it to be handed to you, but you expect to be treated with a little respect," says Shiffman.

Experienced professional actors, of course, do not necessarily expect to be treated with a little respect. They have learned better. Acting takes the universal humiliations of joblessness and job-seeking and builds them into a life-long routine.

Carol Ness, co-owner of one of Washington's largest radio and TV casting agencies, with the improbable name "Central Casting," says her firm maintains a file of 1,000 actors, regularly uses a nucleus of about 200, and keeps about 5 of the 40 or so resumes left there every week.

"If you're 5-foot-2 and you're a male, you're not going to get much work," she says. And beards, too, are out, she adds.

"I feel so sorry for these starving actors," says Ness. But it would be wrong, in her view, to blame their plight on Washington. There is more feature film production going on here than in any other cities except Los Angeles and New York, she says. "Washington is a very sexy city for Hollywood just now.... There's no good place to be an actor. It's a grind wherever you are."

Vance feels that the professional, union theater companies in Washington are closed to local actors. "That's what flips me out," she says. "To work at Arena Stage in D.C. you have to go to New York to audition for them."

But Arena's David Chambers says that's "not at all true."

"We really make every effort to see local actors," he says. "It's a priority of mine." Arena conducts weekly auditions here, he says, and staff members try to get out to see productions at New Playwrights and other non-union theaters in the area.

Arena's LORT (League of Resident Theaters) contract with Actors Equity means most cast members have to be Equity members, but if the theater seriously wants to hire a non-Equity person and has exceeded its quota, it will help the actor join the union, according to Chambers.

And, he wants to point out, Arena has a resident company of 15 to 20 Washington-based actors.

Vance is now subsisting on a CETA grant. Shiffman gets by with help from his wife, an office manager for PRC. For the time being, at least, their waiter and waitress days are behind them.

"Grownups," meanwhile, has been undergoing changes. Vance, Shiffman and Grundmann are busy replacing weak material with strong material (that's what they hope they're doing, at any rate) and beaming their hopes toward a September showcase date at Reno Sweeney's in New York.

If that engagement unfolds according to plan, leading to other nightclub dates and the acquisition of an agent, all three are prepared, at more or less a moment's notice, to move north.

"Whereever "Grownups' goes, we go," says Shiffman. CAPTION: Picture, Vance and Shiffman: "We want to work." By Gerald Martineau - The Washington Post