Back from the Dead (1957)

"Did she come back to LOVE or KILL? His First Wife In His Second Wife's Body!"

A woman is possessed by the spirt of her husband's deceased first wife, turning her into a cold, scheming flirt who will stop at nothing to get what she wants. The woman's sister, husband and the sister's new boyfriend struggle with accepting what has happened, who has caused it and how to correct it, which soon brings them into contact with a coven of devil-worshippers and forces of the supernatural.