These old systems are rapidly becoming obsolete. I believe the relays are a GE type but the switches are very hard to find. The problem you will have is that were wired on the job site in one of two ways. 1. There are relays install at each ceiling j box and that would control the light in that room. 2. There would be a central relay panel that all the relays are there but the problem can be that there may be a central switching point in a bedroom that you can turn any light in the house on. There panels are usually a mess.
The relays are a latching type which the push on latches it and push off unlatches it.
You can convert these monsters by installing a standard toggle switch and a small continuous duty relay to replace the tubual type. I have had to do this a few times and at some point these will need to be changed out
Joe Ogle
