Horror Movie from early 70’s

I saw a movie at a drive in where this lady chops another lady to pieces and hides the body in a sheet in the closet.  A guy comes over and asks where the other lady is.  The killer says upstairs.  The guy finds the dead girl and carries her out to his car.  He goes back in to confront the killer.  She starts screaming and he turns around to see the dead girl standing in the door way with a sheet still around her.  What is it called?  It has been driving me crazy for years.

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