I"m not a heroine -- I just play one. Along with psychotics, vamps, housewives and hookers. As my agent is fond of pointing out, there are more actors in New York than there are people in most other cities. Translation: beggars can"t be choosers. This explains how I wound up prancing around stage half naked the night Golly Gee -- the female lead in the off-Broadway show "Sorceror!" -- disappeared into thin air. Literally. Now other performers are also vanishing, and a mysterious stranger is warning me: There is evil among us. But the producers want me to take over Golly"s part. Looks as if I"m going to need a little magical help if I want to keep my starring role . . .