After I bought a house, I couldn't turn off the dining room chandelier lights for three days while I figured out the box they'd stashed in a cabinet had a radio transmitter that talked to the light. A while later I paid an electrician to run some wire through the ceiling and a wall, and install an outlet with a switch.

There was also an outlet in another room with some complex controls. It stopped working after a while. Turned out the switch - which is connected to a freaking electrical wire - required a battery to work. I had that taken out too, and good riddance to all of it.