Battery main switch off, kitchen lights still on?

[bobbysues]

I have a new FR Sunseeker 2300, Ford E450. recently, I was driving and the kitchen lights came on. when I stopped, I couldn't get them to go out. the switch was off. I even turned off the main battery switch, no luck. I checked the battery connections, toggled the power assist (I think that's what it's called when to push the switch to use the RV battery's to help start the Ford motor). Not sure exactly what I did, but the lights went off, and all the switches work now? I can't reproduce it to take to the shop? anyone ever had this happen, or know how this all works to be able to explain? thanks for any info.