Curtains

Curtains is a 1983 Canadian slasher film directed by Richard Ciupka and Peter R. Simpson, from a screenplay by Robert Guza Jr., and starring John Vernon, Samantha Eggar, Linda Thorson, Lynne Griffin, and Lesleh Donaldson. Centered on the world of theater and filmmaking, its plot focuses on a group of ambitious female performers who are targeted by a masked killer while auditioning for a film role at a prestigious director's mansion.

Synopsis from Wikipedia, CC BY-SA 4.0. Everything below written here.

Poster © the film's rights holders.