I have a living room light switch. It's a one-way switch that controls eight built-in LED lights. This was redone recently (in the last 3-4 years), but the house is new to me, so I don't know anything about how it was done.
There are two things I don't understand:
There are five wires going into this switch. One is obviously the ground, but why are there two wires going into each of the other terminals? (There's another terminal on the other side of the switchbox where you could hook up wire(s) to make it a three-way switch, but that's currently unused. It's not operating as a three-way switch.)
Turning off these lights requires simultaneously turning off two different circuits in the breaker box. If I leave either of the two breakers on, the lights stay on. (This was very confusing when I was trying to figure out which breaker controlled the lights, before I resorted to just flipping all the breakers labelled "lights" at once.)
Is there a sensible explanation for this?
(The context is that I was hoping to replace this switch with a Lutron Caseta smart switch, but the weirdness here has me unsure if that's even possible or sensible.)