Located in the US, I have done some basic rewiring of fixtures and have replaced a few switches in this house. But I am stumped as to what is going on in this box. No idea how to proceed and difficult to find search info that is relevant. Apologies if this is a totally stupid question.
Tried to make clear what connects where in photo using colors they are all black wires - it's hard to see where they go, and how many there are.
Purple - wires coming from the box
White - the first wire from the switch
Red - second wire from switch
Currently in the box - 3 single pole dimmer switches
Switch 1 - single recessed can
Switch 2 - 4 recessed cans
Switch 3 - two exterior lights
Switch #3 is the one I need to swap out, it is broken - I am replacing it with a single pole NON-dimmer (really porch lights are either on or off - no need for dimmer)
Each switch has one black wire individually connected to one in the box with a wire nut (as the others I have swapped out have been)
Except switch #3 connects to two wires from the box (one for each outdoor fixture, I guess?)
One black wire from each switch are (total of 3 wires from switches) bundled together with a single wire nut with two black wires from the box.
All of the ground wires are connected together with a single wire nut, to a single bare copper wire, the rest of the bare wires are neatly bundled together in the back of the box.
There are also five white wires from the box all bundled/connected together with a single wire nut (none go to any of the switches)
All of the other switches I've replaced had a single wire from the box connected to a single wire from the switch with a wire nut. 1 wire to 1 wire - unless it was a single/3way optional switch, where one wire needed to be capped for single pole use.
I had no problem figuring out how to replace a switch with the same type.
My only guess is it's some sort of trick to save room in the box by using fewer wire nuts. Wiring in series? I would like to understand - should anyone have patience to explain or point me in the right direction.
Is this box wired properly? I remember some of these switches being extra buzzy, but not sure it has anything to do with the wiring in the box or is just normal.
Should I just put the new switch in and leave things the way they are?
If yes, what about joining 2 wires to one screw on the new switch? Or add another wire to the wire nut to run a single wire to screw? Errr....that's probably a stupid question. I can figure that out later.