SHE CONTENDED with a creature from space in "E.T." and came to grips with werewolves in "The Howling." Now it seems only natural that Dee Wallace should be up against a killer Saint Bernard.

As the star of "Cujo," Wallace gets mauled savagely and repeatedly by the rabid canine named in the movie's title.

It's a scratch-and-bleed flick depicting three harrowing days during which Wallace and 6-year-old Danny Pintauro are trapped without food or water inside a broken-down Ford Pinto next to a garage on an isolated farm in Maine. Cujo's already ripped to shreds the auto mechanic, the mechanic's best friend and a sheriff's deputy.

And all Dee has is a baseball bat.

The whole thing was enough to drive her clear around the bend.

"After we finished filming, they had to treat me for exhaustion for two months," says Wallace, now enjoying the safety of an overstuffed chair. Her husband, Christopher Stone, who plays her illicit lover in the movie, sits nearby on the sofa in the hotel room, waking up by degrees as he guzzles black coffee.

She's looking fresh and rested, and apple-pie pretty, like the Kansas high school teacher she used to be. Sipping Perrier, she's talking about "Cujo" like a mother discussing her firstborn, and exploding now and then into a shattering, seismic laugh.

A conversation with Dee Wallace can ramble to almost anything: national education policy one minute, and the next, Conceptology, the est-like philosophy she shares with her husband. The dynamics of the conversation are a lot like the "Surprise Symphony," full of eruptions broken by moments of relative calm.

When asked about her first marriage to a man named Wallace, she says with a soft giggle, "You can see I'm becoming very quiet now." But then she gives a sudden shout that makes the interviewer jump: "GO AHEAD, JUST TRY AND PULL IT OUT OF ME!"

And, when the public relations man hands her a review of "Cujo," and it turns out to be favorable, she screams. Not one of your polite screams, mind you, but a full-throated, bloodcurdling "AAAAHEEEEEEEEEE!!" worthy of any in the movie. Everyone in the room stops to stare in amazement. "I'm sorry," she says meekly, and continues reading the review.

The Warner Bros. movie, based on Stephen King's best seller, did enough business last weekend, more than $6 million, to take second place nationwide, barking at the heels of "National Lampoon's Vacation." While it has opened to mixed reviews, it's a big step in the career of the 34-year-old actress, catapulting her--according to a press release--to "the near-top of her profession."

"We were in that car for five weeks, from 5 in the morning till 7 at night," Wallace says. "And we were freezing the whole time. It was raining every day. They sprayed us down with water to make us look like we were sweating. We'd do a scene, and they'd throw blankets over us and turn on little portable heaters.

"And it wasn't one dog. It was five," she says with a mad giggle. "One dog was trained to snarl and growl, another to dig, another to go through the windows. Those dogs were treated better than I was, no joke. Every time one of them finished a scene with all its makeup on, it was washed down and blown dry. The dogs were tranquilized, and there were two veterinarians on the set at all times, checking their little heartbeats and temperatures every 10 minutes.

"One time, we were shooting this scene where the dog comes down on top of me and I'm laying in the dirt with all this crap all over me. This is the hottest scene in the film for me, leading into the climax. So I'm laying there with 210 pounds of Saint Bernard this close to me, and I'm waiting and waiting and waiting for them to say 'Roll!' and my character has started to take over.

"All of a sudden I hear a GRRRRRRRRRGHHH! Well, I took those 210 pounds and rolled them about five feet. Do you think anybody came to me? NO! Everybody ran to the dog." The laughter explodes again. "They threw blankets over the dog. They took the dog's heartbeat. Finally, the vet comes over and says to me, 'It's all right, sweetheart. He's snoring.' It was a real revelation to me to see where everybody ran to."

As she talks, her older brother, a large but mild-looking man named Dennis Bowers, pads about the hotel suite in socks and a three-piece suit. He's president of a health services company in Philadelphia, and he comes in shyly to kiss his sister good morning. She tells him to put Vaseline on his lips.

Christopher Stone, whom she married three years ago after meeting him while filming an episode of "CHiPS," lights up a cigarette. He's handsome and familiar-looking in the manner of a journeyman television actor.

"Living with her is like living in the middle of a crisis clinic," he says with a little grin. Dee, eyes widening, shoots him a glare.

"Oh Christopher," she shrieks, "what a terrible thing to say."

"It's true, but that's not negative," he says consolingly. "I'm not saying that in a negative way. It's just that--"

"Well how do think that's going to look in print?"

"Now already there's a crisis here. She's worried about it."

"Gosh," she sighs, and Stone takes her by the hands and stares meltingly into her eyes. "You're just very emotional," he says.

"The last day of filming in the car," he says, "I woke up around 5 in the morning, and Dee was sitting on the edge of the bed with her head in her hands, and she was sobbing. And I said, 'Honey, what's the matter?' "

"Oh stop," Wallace says, "I'm going to sound so neurotic," but Stone shrugs and goes on. "So Dee said, 'I just can't go back to that car. I just can't do it today.' I mean, she was literally on that very fine edge."

"And you know," Wallace adds, picking up the thread, "I was so connected with the little boy, Danny Pintauro, that when I got to the set, Danny's mother told me that he'd been crying, too, and he didn't want to come back out, either. I can't speak for Chris, but I do believe in reincarnation, and somebody on the set said that if Danny and I had been together in another life, he would have been my father. He's that wise."

DEE Wallace's father in this life was a jack-of-all-trades and itinerant salesman--Dell Comics, Butternut Coffee--who died while she was still in high school in Kansas City, Kan. Her mother was, is, a working woman and amateur actress. Wallace remembers life with father, mother and two brothers as one of hand-me-down clothes, skimpy meals and reusable bath water.

"On Saturday nights, when we'd have to get cleaned up to go to church in the morning, I'd get to take the first bath, because I was the girl," she says. "Then my mother, then the boys in order of their age, then my father--because we couldn't afford to draw enough hot water to take five baths. We weren't poor like India is poor, but we were poor."

Poverty didn't stop her from taking dance and violin lessons and playing in school orchestras, wearing the crowns of the Dell Comics Queen and the Imperial Margarine Princess while modeling part-time and, in her senior year at Wyandotte High, becoming a cheerleader and the homecoming queen and being inducted into the National Honor Society.

"I'm very proud of Didi," said her mother, Maxine Bowers, by phone from Kansas City, where she heads a nonprofit group called Cancer Action Inc. "I just keep telling her that I hope that when she goes completely to the top, she just does it in her own way and stays her own sweet self. I tell her, 'I hope you remember the days when you had to eat a lot of soup.' "

It was her mother, Dee Wallace says, who insisted that she devote her studies at the University of Kansas to becoming a schoolteacher. "My mother desperately needed to know that I was going to have something I could earn a living by. After college, I got a job teaching at Washington High School in Kansas City. I was a very hard teacher. My sophomore kids were doing honors English by the time they graduated."

Wallace kept at it for a year, then decided, "It was time not to live for my mother anymore and take care of this unrest I've always had. I got three summer jobs, sold everything I owned, made as much money as I could and went to New York by myself. I'd never been outside of Kansas before. Sounds sort of like 'Wizard of Oz,' doesn't it? 'Toto, I don't think we're in Kansas anymore.' "

She spent two years in New York before heading for the West Coast, and earned her keep doing commercials and bit parts in the odd TV series. She got the first of a string of big breaks playing a hooker in an episode of "Lou Grant."

Blake Edwards saw her, liked her and cast her as the sad-sack barfly who lusts for Dudley Moore in the hit movie "10." Then producer Daniel Blatt, who made "Cujo," cast her as the werewolf-hassled TV anchorwoman in "The Howling." Then Stephen Spielberg put her in "E.T.," the biggest blockbuster in Hollywood history.

In "Cujo," Wallace is getting star treatment, with her name above the title, plus a handsome salary and a small percentage of the profits. "Which means that if the movie makes $100 million, we get $47.50," her husband says. Says Wallace, "I'm not making as much as Meryl Streep or Dustin Hoffman, but I'm making a lot." She says she commands considerably more than the $50,000 she was paid for "The Howling."

She and Stone, who live in Woodland Hills, Calif., a rich suburb of Los Angeles, attribute much of their success to Conceptology, a quasi-religion that was started by San Antonio chiropractor Thurman Fleets and features such concepts as "vegetable phase," "electrical phase" and "imaging."

"Basically, it's positive thinking," says Wallace, looking over at Stone, who gives a supportive nod. "I've been involved with it since I met Christopher. He's on a much higher level. I'm still scratching my way up. Basically, if you are coming from a positive place of love . . . " She trails off, looking a bit flustered. "Help me."

"It's all right," says Stone. "It's very hard to put into a few words. Meditation is part of it, but you also keep reading and reading. There are a bunch of texts. It's like learning your multiplication tables."

Wallace adds, "It's based on universal truths that never change. There are seven phases. And imaging. And you must get yourself to the point of balance. When the things around you are changing, you remain a constant. You can dictate how you'll react to things."

At this point, the public relations man, looking worried, says Wallace is late for another engagement. He takes her by the hand and practically pulls her out the door. She says goodbye, but Stone sticks around to explain more about Conceptology and his wife.

"Hollywood has absolutely no idea of the depth of her talent," he confides in the tone of a man giving an inside tip on pork belly futures. "I knew it the first time I saw her on film. They have not yet scratched the surface. She's going to be a major, major star. I'm talking Bette Davis. She's going to be a giant star."