"HALLOWEEN" IS suffering from schizophrenia; it can't decide if it's a cult movie or simply a pedestrain box-office smash.

"It's probably a cult movie in reverse," concluded David Levy, owner of the Key Theater in Georgetown. "Cult movies are supposed to take time to build and this is simply too big to be a cult movie now. But it has a hardcore following of horror-film aficionados, who will still be there long after everyone else has died away."

"Halloween's" problem is this: Although endowed with some unmistakable ingredients of a midnight classic, it has already grossed over $12 million since it was released last Halloween -- an obscene amount of lucre for any sefl respecting cult film to make in six months.

Made on less than $1 million, without one bankable star, "Halloween" has been on Variety's list of the 50 top grossing films in the country for the past 18 weeks.

To put this in perspective, the legendary "Night of the Living Dead," George Romero's schlock horror classic, grossed under $5 million during its two years on Variety's charts before its copyright problems became so byzantine that it fell into the public domain and beyond financial scrutiny. Anyone with a copy can now distribute it.

"Night of the Living Dead" has grossed millions since it opened in 1968, to be sure; it has been translated into 17 languages. But it has taken years and countless midnight shows to become a big moneymaker.

"The Texas Chainsaw Massacres," another gory film with a hardcore following, has grossed somewhere over $10 million in the five years since it was released and continues to make modest amounts at drive-ins and on late night television.

Enter John Carpenter and his no-name sleeper, "Halloween." Watch him walk off with $123,000 during the first three days that it opened in the Boston area and $2 million in the Chicago-Milwaukee area alone in half a year.

Critics add to the conclusion by being hopelessly divided over the value of the film. But that in itself is good for sales. Pauline Kael of the New Yorker savaged "Halloween" in one of her reviews last month. But she directed her barbs at those nameless people who think that it has a cult potential. In effect, she acknowledged that it has something going for it, albeit repugnant to her.

"A lot of people seem to be convinced that 'Halloween' is something special -- a classic" she wrote. "Maybe when a horror film is stripped of everything but dumb scariness -- when it isn't ashamed to revie the stalest device of the genre (the escaped lunatic) -- it satisfies part of the audience in a more basic, childish way than sophisticated horror pictures do."

A prime target of Kael's wrath is Tom Allen of the Village Voice, who first discovered "Halloween" and wrote that "it stands alone in the past decade with George A. Romero's 'Night of the Living Dead' and, before that, with 'Psycho.'"

David Ansen of Newsweek, another "Halloween" fan, called it "one of the scariest flicks in years." "It's a classic grade-B movie with absolutely no pretensions," he concluded.

"You've got reviewers reacting to other reviewers, which is always a good sign," said Peter Kastoff, the man who orchestrates the distribution of "Halloween" for Compass International in Los Angeles.

It would appear that the American public likes the "dumb scariness" of "Halloween"; low-brow brutality has always fared well with audiences in this country. But combine a virtually no-name cast (Donald Pleasance does appear in it), timeless and simplistic terror with underwhelming acting and you're inviting the unswerving loyalty of horror devotees as well. "Halloween" appears to have captured both audiences.

Meanwhile Kastoff is running a piece that would make Anne Corio jealous. He eschews the saturation-distribution technique of "Jaws" that would splash "Halloween" all over billboards and theater marquees. While that route would be lucrative in the short run, he feels that it would lead "Halloween" to the pastures of late-night television long before its time. Instead, he is running the film sparingly and hopes to milk a little less for a lot longer. He assures us that we won't be seeing it one television for years to come.

After a brief, unspectacular opening last Halloween at a Broadway theater, Kastoff pulled the movie out of New York completely until late in the fall, when it reappeared at the Arty Eighth Street Playhouse along with that redoubtable cult film, "The Rocky Horror Picture Show." After a two month run there, it was pulled again and will not be seen in New York at all until next Halloween, when it will reappear as part of a nationwide promotion.

"It could almost be a seasonal thing," Kastoff said. "We could run it every Halloween for a while and then pull it."

Kastoff operates on the less is more principle, which in this case, appears to be as good as gold. A little "dumb scariness" goes a long way. CAPTION: Picture, "Halloween": $12 million in six months.