I would suggest that those who have never seen a switch rated for both AC and DC look up JR Products on line and read the specs for the switches they offer for RV use. You might try looking up Sigma also.
Twenty years ago there were hundreds of thousands of relays used for switching power for traffic signal lights. The better relays used a silver alloy for the contacts and they were replaced by solid state relay because they were switching on and off under a load and causing metal transfer between the contacts.
Today's solid state switches use what is called a soft start, no current flow when the gate is turned on and current rises at a very rapid rate. A zero start is better for not only the relay contacts but it was easier on the filaments of incandescent lamps and they lasted longer. Electro-mechanical relays cannot do this with any consistency and neither can manual switches.
Every one of the members of this forum who is qualified on Submarines can attest to how the power to propulsion motors are always started at "0" volts and "0" amps. The amperage can rise very fast after the contacts are made but making or breaking at say 1500 amps can be catastrophic. Submarines to not take well to catastrophic events.
I would guess that a residential on/off wall switch rated for 15 amps, would be capable of carrying about 5 amps at 12 VDC.
