I guess when the house was wired in the 1930's, and an addition was added in the 1950's, and renovations to make the two-part duplex into a giant house with a small inlaw's suite (which is said bathroom I wired up today), and even when my uncle lived in there from the 80's on up to 2015... the only real "electric" in there was a wire that ran from the kitchen light beside it with the switch removed and the wires tied together, across that ceiling, part way down the wall, into the bathroom, and connected to a medicine cabinet with a built in light and one receptacle from the 70's.
All that fresh new wiring... new boxes, switches, GFCI, and (soon to be) vanity light, as well as a vent fan with light... connected to a fuse panel from I am guessing the 1950's.
That'll be upgraded soon too, at least. Thankfully I was able to find an unused fuse IN that panel...