How to diagnose a lightswitch that appears to do nothing
A switch is required by code in most places for most rooms - that way you automatically know how to easily turn on the light. But code does not (generally) mandate a particular lighting method, so many builders don't bother to put in the light fixture and just connect the switch to a receptacle for the homeowner to plug in a lamp. One of the first things I did after moving into my house (and I was not the first owner - people just don't realize they can change things, I guess) was to have ceiling lights installed in the bedrooms and connect the existing switches to them and disconnect the switches from the receptacles.
Three likely possibilities:

The switch was disconnected from whatever it originally switched. This could be an originally switched receptacle or it could be the ceiling fixture - e.g., to always be able to use the remote and not have a problem of being unable to turn it on with the remote because somebody had turned off the switch. If that's the case then if you open the switch you will either find no wires connected to the switch (i.e., disconnected from the switch and now bypassing the switch) or wires connected to the switch but none of them with any power (i.e., a non-contact voltage tester will show nothing on any of the wires).

The switch is supposed to control half of a receptacle. The receptacle was replaced at some time (to fix a broken receptacle, or for a different color to match new paint, or whatever) and the tab connecting the top &amp; bottom hot screws was not removed.

The switch is supposed to control an entire receptacle. The wiring was redone at the receptacle at some time in order to make the receptacle always hot but the switch wires were left in place.