It's a black-and-white film. There's a group of scientists/astronauts/technicians wearing hazmat/space suits. They're in some sort of lab or factory doing research or fixing something. They take turns looking into some hole. One after another, each person turns into a faceless zombie-like version of himself with electricity sparking inside their helmets like a plasma orb.
I remember watching this one many years ago. I did some research online and concluded that is not a Twilight Zone episode. I would like to know what movie/show this is.