Yes, I found the fuse for my basement lights.
It is in the Battery Control Center box above the coach batteries. I found a one-page schematic with my manual that showed the wiring in the "BCC". There are 6-8 other fuses inside for other things. Of course, there are several in-line fuses above the batteries and in the engine compartment. The only one I have figured out is the 25 amp fuse to the automatic steps.
BTW, I had to pay a service call last weekend because my leveling jacks would not retract. Turns out the circuit breaker to the hydraulic pump had tripped. It is located to the left of the BCC. There is another breaker below it but don't know yet what it goes to. Paid the tech $180 to find the breaker and reset it.
I trying to learn all I can about the electrical systems in the RV but it's not easy. I wish Forest River offered more information.