And you can put a flasher from NAPA in those two holes and the lights will flash! NO HARM to your electric stuff. You are just putting 12 volts from the batteries to the running lights. You can do the same thing with out shore power, but keep an eye on your batteries!
Oh, yeah - you don't need to use a fuse as the lights have their own fuses in the trailer...I just use a piece of jumper wire that I keep in the glove compartment.
I think it is kinda cool for special occasions, but a bit over the top for this introvert...