The Devil Commands (1941)

Starring Boris Karloff, Richard Fiske, Amanda Duff, Anne Revere, Ralph Penney
Directed by Edward Dmytryk
(actor & director credits courtesy IMDB.com)

A university science professor is convinced his device for recording thought waves has captured transmissions from his dead wife, and takes desperate measures to try and communicate with her.

Another of Karloff's low-budget "mad doctor" pictures for Columbia, the film may be most notable for being helmed by Dmytryk, who would later be nominated for an Oscar, and also imprisoned in the HUAC attacks on Hollywood in the 1950s.  The story has a great genesis, embracing the worthy idea of scientific communication with the dead, and I enjoyed how it was staged, although Karloff's subservience to Anne Revere's character late in the film could have been better explored and portrayed, rather than focusing on the old chestnut of angry villagers forming a mob against the scientist.  My favorite part of the picture was Karloff's scenes with his screen wife, Shirley Warde.  Not only is she well-cast, bringing a distinguished and vivacious spirit to her character, but she has wonderful chemistry with Boris, who throughout his career didn't get many chances to portray a man in a loving relationship.