she's mighty mighty, lettin' it all hang out

my old house is built of lath and plaster, (more like cement, actually), with square nails, knob and tube, and plenty of coal dust just to make things annoying. my light switches (one which turned on when off, and off when on) finally gave up the ghost. i bought the goods to fix it myself, but once i started, it was clearly a professional's job. now i have someone to blame for the crooked switches and the giant hole in the wall.

how could so much stuff fit behind that switch? it's an electrical miracle. see the virgin mary in that hunk of plaster?