I recently bought a 1951 home. There is a switch in the living room that appears to have been intended to control one or more outlets in the room (the switch affects no lights and all lights are controlled by other switches). However, the switch does not affect the outlets either: whether the switch is on or off, all outlets are on.
The outlets are all wired with either two black and two white wires or one white and one black. There are no red wires like you'd see with a typical newer switch-to-outlet configurations. The switch, which is a new replacement, is wired with two black, and the two white are capped off together. The bottom black wire for the switch does receive electricity. But again, no red wire at the switch box.
Other than incorrect wiring, is there a possible explanation in an older home as to why the wires would be configured and would function this way? Is it possible that it is in fact correctly wired to operate outlets but the outlet being controlled would have to be installed a specific way (eg, removing the bridge between the two hot terminals)?
Best Answer
Yes, most older houses were wired with half-switched outlets because they did not have switched overhead lights.
It's entirely possible that someone replaced the receptacles with new ones and did not break off the tabs between the 2 halves of the outlets, thus both top & bottom outlets are always live.
Using red insulated wire to go to the switched receptacle was a convenience, but I don't believe it was ever required by code, thus there's no reason for you to be concerned about the fact that there aren't any /3 cables leaving your switches. Actually, in 1951, most (all?) wiring would have been individual wires with cloth insulation, not the modern NM cables with multiple, individually insulated wires within a sheath, so it's even less surprising that you're not seeing a red wire.
The outlets with 2 pair (white/black) of wires are somewhere in the middle of the run - power comes in on one pair, provides power to this outlet, then carries power on to the next outlet in the string.
The outlets with 1 pair (white/black) of wires are at the end of the string. Power comes in and is provided to the outlet, but doesn't need to carry on to another outlet.