[TOMT] Name of 80s TV movie with demon-detecting helmet
I remember seeing some 1980s movie on TV (or maybe a made-for-TV movie) and all I remember was a husband had invented a helmet that could detect demonic possession or something similar, and his wife and child got possessed or replaced or something. The scene that sticks out in my mind is the husband and his family exit a room, and the camera is in a position where you can see the helmet visor's readout, and you can see it scanning and detecting the husband as normal but wife and kid as not. It seems like a crazy, fantastical scene but I know 80s TV could be weird like that sometimes!
Anyone remember this show?