As someone said, here in northern NJ they use to install these LV lighting controls all the time. It was a big rage around the '60's I believe. I have seen and worked on several styles of those relays. I believe Amprobe even made some of those relays. There was a trade name of Remcon Relays. By the doors of the rooms there was 1-5 push buttons and you could control any light fixture you wanted from any door if you so desired. Usually the lighting control box was in the attic with a ton of those little relays attached to it. Each relay had a tag to tell which light fixture it controlled. The biggest problem with that is, when I go there the tags had fallen off and it was a hunt and peck routine to try and find the correct relay.
