Nightmare Castle (1965)

A woman and her lover are tortured and killed by her sadistic husband. The pair return from the grave to seek vengeance.

Director:

 Mario Caiano (as Allen Grünewald)

Writers:

 Mario Caiano (story), Fabio De Agostini (story)

Stars:

 Barbara Steele, Paul Muller, Helga Liné - via IMDB

https://archive.org/details/nightmare_castle