House of the Seven Corpses 1974
Low Budget feature starring John Ireland as a director filming a film on location in a house where seven murders were committed. John Carradine is the caretaker who warns them not to mess with things they do not understand(the murders were occult related)but Ireland wants to be as authentic as possible and has his cast re-enact rituals that took place in the house thus summoning a ghoul from the nearby cemetery to bump the whole film crew off one by one.