Do you get martens near you? I quite like them but they have a habit of eating wiring looms like that. You can get little 12v ultrasonic boxes to deter them that wire up to the battery.Reversing light kept blowing fuses.
Poxy mice.
So I ensured the Passenger Management Control Module was activated...
I've got a picture somewhere of a merc van chassis with a nest in the chassis rail via a missing bung, with a stash of stolen eggs and the rear lights wiring loom eaten by the entry point, now the motorhome etc has one not had any more incidents.