Electrical Unused light switch in the living room?

[arabianights]

hi guys

I have a switch mounted on the wall in my living room that doesn't control anything, it's on the opposite side of stairwell to the basement and below the HVAC vent. the light switch to stairwell is in the same space of stairs. and the living room ceiling light is controlled on the far side near the kitchen.

the townhouse was built by Pulte in the mid 80s if that helps.

 

[berkeman]

How do you know it is unused? When you pull the plastic faceplate off, do you see any wires going to the switch? (Don't pull the switch itself out of the wall.)

Oftentimes, such a switch will control an outlet, so that a floor lamp can be controlled via the wall switch. Are there any outlets nearby? Can you use a socket tester or even just a lamp to test to see whether the switch is controlling it?

 

[Averagesupernova]

It's not uncommon for a receptacle to be split. For instance the bottom may be live all the time but the top is controlled by the switch.

 

[Borek]

First thing I would do would be to check it with a wire detector (few bucks for a basic model).