Update -
I found it, it was reversed polarity and no ground. I was mistaken about making a new home run to the breaker box, that was for something else, I didn't wire this. But I had to buy another multi-meter the old one I was using quit working, and the first thing I checked was polarity and ground.
Whoever wired it had the wires on the right side of the box but the plug itself was upside down and the ground wire was not connected. I put in a new outlet, wired it right, and I took off the earth ground to the RV outside and no more shock, everything is good now. I did check the RV to the Earh ground with the multi meter, no current now.
Thanks everyone!!