My daughter and SIL just bought their first house, and they’re in the process of painting and starting to move their crap OUT OF MY HOUSE!!!
Ever the helpful parental units, we’ve been lending a hand with some of it. And one thing we’re trying to figure out is WTF previous owners did with the wall switches. Apparently a bunch of them control outlets. According to my daughter, the top plugs connect to the switches, but the bottom ones are always hot. Every outlet in the living room is wired to a single switch.
The switch in the master bedroom doesn’t control the ceiling fan or light. In fact, we can’t figure out what controls them. The two switches that control the closet lights are wired to a plug that’s plugged into an outlet next to the closets. The ceiling fan in the baby’s room has a remote, but the switch doesn’t connect to the fan at all. And barely 8’ apart in the hallway are two switches, both of which control the single hallway light.
But there’s another switch in the hall that doesn’t seem to do anything. There are no outlets in the hall, so that’s not it. Neither the coat closet nor the linen closet are lighted, so that’s not it either. If it controls an outlet somewhere, that should be simple enough to figure out - we just plug lamps into all the sockets and flip switches. beyond that, I have no idea how to figure it out, short of climbing into the attic.
We had a house in Virginia in the late 90s and it had a switch in the hall outside the half bathroom. We never did figure out what it was for. Come to think of it, we never even checked to see if it had power to it. Not that it matters - we sold that place in 2000.
Share your tales of mystery switches, plus any suggestions on how to figure out the mystery switch.
At my folks house (where I grew up) there’s a switch on the wall at the bottom of the stairs (it’s a short flight of 6 steps) that doesn’t do anything.
When I lived there it used to control a lite at the top of the stairs. When they remodeled, they removed the lite as it was almost never used and didn’t match the decor, but left the switch.
Maybe it’s something like that.
Or…
in my house there’s this light switch that doesn’t do anything. Every so often I would flick it on and off just to check. Yesterday, I got a call from a woman in Madagascar. She said, ‘Cut it out.’
We bought a house from a coworker. He warned us that there was one switch that they screwed up when they remodeled the 3 season room into the dining room and extended the living room. They bought a 4 switch outlet and box, when they only needed 3. So they installed it anyway.
There was a rotational switch behind our bathroom door. Out of 7 neighbors, some of who have lived in this building since it was built, none of them knew what it was.
We found out when we remodeled. It was a switch for the water cutoff for the washer, as the water cutoff is behind the washer and not actually reachable.
It was not connected. None of them are. We now have a water cutoff that is above the dryer, which is above the washer. So it’s difficult to reach, at least for someone under 6’, but at least we don’t have to move the washer.
When my late father rewired our new-to-us 1928 house (yay knob-and-tube) the top of the outlets in the front of the house were controlled by a time clock.
He did it that way for the Christmas candles. Put them in after turkey day, removed them after New Years, and didn’t have to touch anything in between.
The house I grew up in had a switch in the hallway that used to control the flood light on the back of the house. Then my parents built an addition on the back of the house, and that flood light got removed in the process. The switch is still there, but it no longer does anything. When my parents sold the house I imagined the new owners were going crazy trying to figure out what that switch did.
Come to think of it, even when the flood light was there, it wasn’t really obvious that’s what that switch was for. You couldn’t actually see the flood light from the hallway, so you could only figure out what it did if you turned it on and then went to the kitchen and looked outside, or if someone else was looking out the window when you turned it on.
My contractor hated me so he put a couple of plug-ins in that don’t work and 2 light switches you have go in the room shut the door and flip the switch that’s behind the door. I have a sign on my half bath door to inform guests of this problem.
Putting outlets and light switches is difficult in a log house so we’ve just learned to live with it.
I hate that contractor guy.
One of my favorite things about electrical hardware in the UK is that standard wall receptacles have an integrated on/off switch. I wish that were the norm for US usage.
Some years ago, I (GLS) was snooping around in the cabinets that housed the MIT AI Lab’s PDP-10, and noticed a little switch glued to the frame of one cabinet. It was obviously a homebrew job, added by one of the lab’s hardware hackers (no one knows who). [it was Tom Knight]
You don’t touch an unknown switch on a computer without knowing what it does, because you might crash the computer. The switch was labeled in a most unhelpful way. It had two positions, and scrawled in pencil on the metal switch body were the words ‘magic’ and ‘more magic’. The switch was in the ‘more magic’ position.
I called another hacker over to look at it. He had never seen the switch before either. Closer examination revealed that the switch had only one wire running to it! The other end of the wire did disappear into the maze of wires inside the computer, but it’s a basic fact of electricity that a switch can’t do anything unless there are two wires connected to it. This switch had a wire connected on one side and no wire on its other side.
It was clear that this switch was someone’s idea of a silly joke. Convinced by our reasoning that the switch was inoperative, we flipped it. The computer instantly crashed.
Imagine our utter astonishment. We wrote it off as coincidence, but nevertheless restored the switch to the ‘more magic’ position before reviving the computer.
A year later, I told this story to yet another hacker, David Moon as I recall. He clearly doubted my sanity, or suspected me of a supernatural belief in the power of this switch, or perhaps thought I was fooling him with a bogus saga. To prove it to him, I showed him the very switch, still glued to the cabinet frame with only one wire connected to it, still in the ‘more magic’ position. We scrutinized the switch and its lone connection, and found that the other end of the wire, though connected to the computer wiring, was connected to a ground pin. That clearly made the switch doubly useless: not only was it electrically nonoperative, but it was connected to a place that couldn’t affect anything anyway. So we flipped the switch.
The computer promptly crashed.
This time we ran for Richard Greenblatt, a long-time MIT hacker, who was close at hand. He had never noticed the switch before, either. He inspected it, concluded it was useless, got some diagonal cutters and diked it out. We then revived the computer and it has run fine ever since.
We still don’t know how the switch crashed the machine. There is a theory that some circuit near the ground pin was marginal, and flipping the switch changed the electrical capacitance enough to upset the circuit as millionth-of-a-second pulses went through it. But we’ll never know for sure; all we can really say is that the switch was magic.
I still have that switch in my basement. Maybe I’m silly, but I usually keep it set on ‘more magic’.
We finally found out that a switch in the living room was for the fireplace fan, if we ever wanted to have such a fan installed. As for light switches 8 feet apart, in our place, you can turn the light on in the dark hall when you come in the door, then walk 8 feet and turn off the light that is now behind you without having to retrace your steps, hit the switch, then bumble forward in the dark. This is often useful.
My Son’s house has a timer in the hall for, a long ago removed, attic fan.
He taped a sign above it that says: “Time bomb control. Do not touch”
He says 9 times out of 10, people will touch it. Some even turn the knob.
Humans don’t follow direction good.
I had the same experience, although we didn’t add anything to the house. I was going to suggest to FCM to also check outside outlets.
I find a nightlight good for this sort of testing.
In my current house, I was trying to determine what switches did what - there was one switch in the living room that I wasn’t able to see it do anything, so I used a multimeter to see what was going on. It was on when the switch was up or down, and off only in the middle. And if I put it in the middle, the main light in the living room turned off. Figured out it was a three way switch wired into the same light as the two way switch across the room, thus the “always on” value. There’s a thread in GQ from 20 years ago talking about it.
We have a switch in our foyer that as far as I have been able to tell, doesn’t do anything. The other switches there (there are 6) control the inside foyer light, the side porch light, the back deck light and the two outside floodlights that are attached to the house. My best guess is that the last one was intended to go to an outside driveway light/lamppost, and it was either removed or never installed in the first place.
Our house was previously owned by an “amateur” electrician, and had too many electrical quirks to mention. Like receptacles wired with LAMP WIRE, connected to lines in the basement. Even today, nobody can figure out the light over the kitchen sink and the adjoining switch/receptacle, both of which seem to be connected to the ceiling light/fan in an upstairs bedroom.
Oh, and this same former owner had painting the entire basement with metallic silver paint.
I read a story once, and I think it was here, where the unknown switch turned out to be for a heating element under the front sidewalk to clear snow in the winter.
They figured it out one night when drawn to the catfight where the neighborhood strays were sleeping on the conveniently warm concrete.
