I'm trying to find a movie about some teens who go to an island dig up a dead guy and party with him they do some incantation to reanimate him but something happens and they reanimate the whole cemetery outside of the house they are in

Children Shouldn't Play with Dead Things (1972)
Wikipedia synopsis:
The story focuses on a theatre troupe, led by Alan (Alan Ormsby). He is a mean-spirited director, who travels with the others by boat to a small island for buried criminals to have a night of fun and games. Once on the island Alan tells his group--he calls them his "children"--numerous stories relating to the island's history and buried inhabitants. At midnight using a grimoire, Alan begins a séance to raise the dead after digging up the body of a man named Orville Dunworth (Seth Sklarey). Though the original intent of the ritual may have been solely as a joke, Alan appears disappointed that nothing happens.Afterwards the party continues and Alan goes to extremes to degrade the actors, using the corpse of Orville for his own sick jokes. Then, animated by the fell ritual, the dead return to life and force the troupe to take refuge in the old house.. .

Children Shouldn't Play with Dead Things - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Children_Shouldn%27t_Play_with_Dead_Things)