Pardon My Brush 1964
Two dimwitted house painters are hired to paint an apartment hotel. It turns out that the hotel’s residents consist entirely of beautiful women. The two painters inadvertently mix vanishing cream into their paint, and discover that when they paint the walls they become transparent, allowing then to observe the girls doing their daily “routines”–exercising, showering, etc.
Yvonne Craig in The Good Guys (1969) episode - Communications Gap