Fright Night (1985)
Charley Brewster (William Ragsdale) believes that his next-door neighbor Jerry Dandridge (Chris Sarandon) is a vampire. His belief is strengthened when mysterious deaths of girls are reported. When Dandridge confronts Charley in his own bedroom one night and tries to kill him, Charley concludes that the monster must be destroyed. But since nobody believes his story, he enlists the help of Peter Vincent, the vampire killer from his favorite horror TV show, who is, in fact, skeptical about vampires existing for real.