Quote Originally Posted by Mike Noland View Post
It's about 30 yards from the house where it is powered from.
My guess is that without a sub panel near the outlet, you don’t have a ground rod there and you are seeing a voltage difference in the soil. If you have a voltmeter, measure from ground to hot on the outlet and you should see about 120v. Plug the camper in and plug an extension cord into an outlet in the camper that will reach the steps. Measure from the steps to the hot lead on the cord. Again, should be 120v. If both of these work out, you confirmed the ground is intact at the receptacle and in the camper.

Now to check for ground voltage difference. Drive something like a tent stake into the soil near the steps. Measure AC voltage from the steps to the stake. Ideally you will see zero volts. My bet is you will get a higher voltage.