Thanks for all the replies,
What I am finding is that because the 120 volt AC common and ground are not connected in a RV the ground is connected to the chassis as is the ground for the 12 volt DC.
It should work fine. "A ground is a ground" The only problem is when I forget why I did it next week.
The reason for the power point is to get power near the bed for my cpap machine. The machine pulls 2 amps without the humidifier and 5 amps with the humidifier. I will try not to use the humidifier.
Reminds me of a story,
One of our firefighters said that she would get shocked when she got into the engine at the station. None of the other firefighters complained about it. I went to the station and got into the engine and nothing. Asked for her to come out and show me. She walks out in her stocking feet. So the diagnostician that I am I took one boot off and grabbed the handle. Yes she she was not lying. We found an open ground at the shore line connector.
Ed