two things come to mind did you have the electrics proffessionally fitted ? and is it the new style 13 pin plug? mostly lights coming on unexpectedly are usually caused by a faulty earth somewhere in the system hence the proffession question as incorrect wiring on the thin wires of modern cars can cause major problems [expensive] so best to go to a towbar expert but you could first try someone elses trailer or even a trailer board to make sure it isnt the camper with a bad wire
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