The Amazing Mr. X (1948)

Two years after her husband's death, Christine Faber (Lynn Bari) thinks she hears her late husband (Donald Curtis) calling out of the surf on the beach one night. She meets a tall dark man named Alexis (Turhan Bey) who seems to know all about her.
After more ghostly manifestations, Christine and her younger sister (Cathy O'Donnell) become enmeshed in the strange life of Alexis; but he in turn finds himself manipulated into deeper devilry than he had in mind.