For AC runs I use the floor cabinets. For overhead runs, all 12 volt, I have overhead shelves starting with the one over the door that go from the couch all around the trailer through cabinets or shelves back to the front of the trailer.
As well there are a couple of instances where I have wires that run on the bottom of the trailer. One example is the cable for the TV which just runs along the bottom to the rear of the trailer.
In another case I wanted to take an AC line from the breaker box to the couch for a wall outlet box and an outlet box for the Convertor. In this case I ran the AC under the doorway incasing it in a plastic run and attaching it to the bottom of the floor. When I drill a hole thru the floor for wires I paint
the inside of the hole and fill it with goop after I run the wire. I use all 14 gauge AC house wire with ground because it's easier to run and wire. My four breakers are all 15 amp.