The light and fan work perfectly, but I was looking to fix a downstream light that has has no power (as I'm a new homeowner) and encountered this strange situation when I started pulling switches out.
Using a non-contact tester (that I verified works with other wires/outlets in the house), I find no hot wires when the light switch is on (and the lights/fan are on) but when I turn the light switch off (and the lights/fan turn off) one of the wires becomes hot. I'm stumped to how such a configuration could even be possible.
The light switch does work with a ceiling fan (where one switch controls on/off and a remote/cord controls the fans speed).
What could be causing this? It doesn't seem to be reversed polarity or any other electrical term I can think of/find on Google. The house was built in the 1920s, so there could definitely be something old/misconfigured.
EDIT: I got a multimeter and measured the voltage. It has 0 voltage when on and 120 voltage when off. Again, I'm not sure how it could have zero voltage when the light is clearly on.
EDIT Again: Along with this posts answer this post, https://community.smartthings.com/t/wiring-question-why-would-a-switch-have-no-power-when-on-and-power-when-off/39897 helped me realize why the multimeter would show voltage when off but not on.