Another word of caution: The 240 volt wire that goes to my pool pump is 12/2 w/ground. The voltage between the black and white wires is 240 volts.
Some dryer outlets are wired the same way.
Always, always test the circuit with a volt meter before you plug your RV into it. Too many stories on these forums of people who have fried every electronic device in their RV by not testing first.
The situation you describe is due to a lazy/incompetent electrician or an inexperienced DIY. The white wire is supposed to be identified as a hot leg (i.e. black tape on white wire, use black heat shrink on the wire, or use a black marker to color the white wire).
When someone says, "I'm not book smart, I'm street smart." All I hear is, "I'm not real smart, I'm imaginary smart."
I would also consider using a 12 volt landscape-type lighting system that is housed in a rainproof NEMA enclosure positioned and located in such a manner as to minimize any risk of water entry. 120vac around water scares the bejeezus out of me.
I second that approach -- and if memory serves me correctly there may be code requirements which may place restrictions on the distance you can place 120 volt stuff near the hot tub. In our case we use solar lighting.
Thanks for all the advice.Actually found a spa box with the gfi breaker and room for 2 120V breakers.All wired up,filled,stereo on,soaking with beer in hand.Now if I could just find a way to get it to work in the toy hauler garage.
"If momma not happy ....Who cares.I have my TH AND my toys .