This may not help, but I had similar incident recently a mouse chewing in the ceiling. Luckily did not eat wires, but some wires run in the AC chase that is preformed in the styrofoam ceiling. Remove all the ceiling AC covers and maybe you can determine which wires and get lucky and snake some new ones.
The styrofoam is easy chewing for the mice as well.
After much searching to determine where the entry point was ( find that first, very important) we determined he was getting on top of the black tank in a 1/2 " space between top of tank and the bottom exterior of the floor. He was then traveling up the black tank vent pipe or chase vertical between the bathroom wall and bunk wall, right before the vent pipe exits the roof, the vent pipe passed through the AC chase, and that is how he gained and had full access for the entire length of the TT. He then traveled from one AC chase to the other by crossing across where the bathroom vent opens. He chewed right around it. He was having a ball up there. Some wires were exposed but not chewed on at all. Hope this helps some. Mine is an 04 Flagstaff Superlite.
Address the entry first, or he will be back, and likely bring all his friends.
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