Working with lathe and plaster
I have a one-gang electrical outlet in my bathroom above the toilet that I want to expand into a two-gang. (I have someone to do the wiring.) As I was unscrewing the screw at the middle back of the gangbox to loosen and remove it, I heard a piece of metal clank to the ground and the box freed up.
I pulled the gangbox out, stuck my hand in, and there is space all around except for the lathe and plaster from the room on the other side of the wall about 6 inches away. I can't figure out A) how the one-gang box was attached and B) how to attach the two-gang box.
Any suggestions for how to proceed?