Thank you to everyone for the suggestions! I will try to answer the questions in the order posted.
1.brokenrule I do have a digital multimeter and I could construct a harness to safely connect to a 120 vac receptacle.
2.SuperGewl We do have the 1K inverter. The DVD is plugged into the receptacle in the front driver's side overhead cabinet (RCP-COMPONENT LEFT ?) , the TV is plugged into the receptacle above the buffet (RCP_TV POWER CONTROLLER ?) and the clock radio is plugged into the receptacle for the rear TV (RCP-BDRM TV ?). The inverter is not turned on. I printed a copy of the wiring diagram years ago, but never fully understood all the options shown.
3.danhannah The electric water heater and microwave appear to be on the same circuit. We have learned not to use both of them at the same time.
I have attached a copy of the wiring diagram for our MH.
Vista 30T.pdf