Massacro (1989)

A prostitute is brutally killed by the road side by a maniancal killer. Nearby a horror film is being produced but the director is worried that the script is too passé for a modern audience and so he plans to include a séance scene - he hires a real medium to carry out a ceremony with the cast and crew to help inspire the script but she is attacked by an evil spirit. Meanwhile members of the cast are being picked off one by one and police detective Walter is desperate to stop his girlfriend, the lead actress Jennifer, becoming the next victim...