I read this in the summer of 93. It was similar to the point horror books, but I went through all the titles I could find. Didnt see it there.
These high school girls are camping out at the cemetery one night. Main girl needs to pee and goes behind a tree. She finds an open grave, a body is lying there and she hears, "hes dead isnt he?" she flips out, runs back to her friends. They go back and grave is empty. The next day, kid in the grave is found dead somewhere else. she meets a guy at school who has a reputation as a rough kid. He ends up being the voice in graveyard, but he didnt kill him. They start dating, and she finds out he spends nights in school basement and plays the sax real well. girl gets a job at supermarket. one of the other employees is an assole kid that is friendly to the older customers. at one point, a customers house is burglarized. Main girl remembers the this customer telling the asshole guy about her trip. the asshole ends up being the killer with his girlfriend. guy in grave was part of a prank, but ended up killed by asshole coworker.