Since these are lights in the slide, and you mention electrical plugs, are you talking 12v or 120v lights?
All 12v DC interior lights would be fused at the house fuse panel. That's the panel that would have fuses for water pump, refrigerator, furnace, water heater, etc.
120v AC lights would be on a circuit breaker in your power panel. Also test and reset all GFI outlets. It would be unusual to protect lights with a GFI outlet, but a possibility.
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI