The Living Ghost (1942)

Wise-cracking ex-detective Nick Trayne is called in to try to find the whereabouts of wealthy kidnap victim Walter Craig. Craig unexpectedly turns up alive but with apparent brain damage, leaving him in a zombified state. Trayne and his perky assistant Billie Hilton have their work cut out for them as they must sift through a houseload of possible suspects to get at the culprit.