This 1957 black and white science fiction movie starred Grant Williams and Randy Stuart as Mr. and Mrs. Scott Carey. Scott gets exposed to some mysterious mist while onboard his brother-in-law’s boat and finds himself beginning to slowly get smaller.
Suddenly his shirts are too big for him and he’s losing weight. The family doctor is played by William Schallert, famous for being the voice of Pop Tarts’ Milton the Toaster. He also played the father on the Patty Duke Show.
He recommends Scott to see a specialist played by Raymond Bailey, recognized as Mr. Drysdale from the Beverly Hillbillies. Eventually, Scott Carey is seen as a freak when he winds up smaller than little people from a nearby traveling circus.
He becomes tiny enough to live inside a dollhouse where the family’s pet cat is viewed as a survival threat. The special effects for the time period are pretty good.
Scott ends up using a straight pin to battle a spider found in the basement. Smaller and smaller into a world with an expanding universe. Not much room left for any kind of happy ending.