I've just been out to look at a camper with electrical problems{tiny shocks from the bodywork}.Bought secondhand and wired by blind pugh,at least it looks like it.
This has proded me into offering to test your caravans/campers etc for electrical safety at a modest cost.
If you would like your caravan/camper tested either PM me or phone 0413738216, by the way I am fully lisenced.