I have a plastic switch box with two circuits going to it.
One circuit is 15 amp which is a 3 way switch and another 2 way switch to control a different light. The other circuit is a 20 amp circuit and currently it has a 3 way switch... but the wires actually were not hooked up to it, but instead just the white and black wires tied together in a single wire nut.
There is no electric running through these wires but I know where the wire for this circuit runs to a outlet a few feet over and it’s on a 20amp breaker. I’m assuming this wire and switch was once used with some other switch to control a light but were eventually removed. I assume this only because I could not find any reason they would just be tied together and did not have power then running through either the hot or neutral.
My only concern is they still used the ground and tied it in with the other 15 amp switches/circuit. Is this allowable considering it’s a 20amp circuit and a 15 amp circuit considering the 15 amp has 14awg wire?
Seems if there was a ground fault it is a fire hazard for the high gauge wire. Also the ground from the 15 amp circuit seems to have 50 volts running through it so potentially a leak somewhere in that circuit which is carrying over to the 20 amp circuit.