electrical key switch
 

I am buying a home in the Phoenix area that was built in 1948, it has an electrical box in the bedroom that has the company name Sentrol, Inc on it with the address in Portland, phone number, and a date of "September 13, 1976" stamped on the side. Company no longer in business, so not too much to say there.

However, downstairs there's a stainless steel electrical key switch with a red light and a green light just above the circular key hole. Electricity is still off, so playing around is hard to do. It looks like a switch you would see in a hospital, did security systems used to have those kinds of switches in the 70's?

Sentrol is a GE owned brand of security products. Sounds like there is or was a security system of some sort in the house. You might look for a panel with the actual system workings in it.

Yes. Ace lock (among other names).