By GINIA BELLAFANTE

For struggling New York actors, a "normal" job is spritzing cologne at Macy's or delivering Mylar birthday balloons to small children. But when STEVE BUSCEMI was creating a name for himself on the lower Manhattan theater scene of the '80s, he took an even more unconventional route to pay the rent: he became a fire fighter. "It was the only job I've ever had that compared with the real high I get when I'm acting," says Buscemi. With two critically praised films out simultaneously, the talented actor must be soaring these days. Father of a two-year-old son, he has quietly become a prominent face in the independent-film world. In the new low-budget comedy In the Soup, Buscemi stars as an aspiring moviemaker who has lots of trouble interesting anyone in an esoteric 500-page script. And in the grittier flick Reservoir Dogs, Buscemi does quite a job portraying an oddly logical thief and killer who seems to have a deeply rooted problem with tipping. Moviegoers clearly owe a big thank-you to the Big Apple's fire department for never naming Buscemi its chief.