One of My Wives Is Missing (1976)

12 million reasons for murder!

Vacationing in a small town, a frantic Daniel Corban shows up at the local police station, declaring that his wife has disappeared. Corban imperiously demands that the easygoing police inspector drop everything and find his missing spouse. Within a few days, a woman claiming to be his wife shows up, but Corban insists that he's never met the woman before.