My place was built in 1940, using the latest in "electrical tech"- the new "Romex."
I've begun some long-overdue remodelling. I thought you'ld appreciate a pic of how things used to be done.
Please note the shape of the rear of the switch box. Note that there are no connectors; while the box has tapped holes for an internal clamp, none was used.
What is not so clear is that this box is just a bit smaller in every dimension than the boxes we use today. A standard "gfci" receptacle will just fit- but there will be no room left for the wire!
Later, I'll try to get some nice pics of how wires were connected before wire-nuts came along.