I bought a house last year and I was somewhat mystified by why the two light switches next to the door were horizontal instead of the normal vertical arrangement. Turns out they had tried to turn a single box into a double by basically just gouging a bigger hole in the cinderblock wall and filling it with a softball-sized lump of caulk into which they stuffed the two switches; somehow they could only get this whole mess to stay in place by putting the switches horizontally. For bonus points, one of the switches did nothing except producing a distant humming noise and then tripping one of the breakers after a few seconds.
arcing in the walls
Yeah, when I rebuilt the kitchen/living room wall, I found the stud that had held one of the original outlets and it was scorched black where the box had been. Kind of amazing the house was still standing.
I did reuse the scorched stud. 2x4s are fucking expensive and these ones from the 1940s were perfectly straight and completely knot-free.
