Secret Beyond The Door [1947]

In this Freudian version of the Bluebeard tale, a young, trust-funded New Yorker goes to Mexico on vacation before marrying an old friend whom she considers a safe choice for a husband. However, there she finds her dream man, a handsome, mysterious stranger who spots her in a crowd. In a matter of a few days they marry, honeymoon, and move to his mansion, to which he has added a wing full of rooms where famous murders took place. She discovers many secrets about the house and her husband, but what she really wants to know is what is in the room her husband always keeps locked.