Many Fleetwood motorhomes (and other brands) have recessed accent lights in the ceilings. If you have this type of light and need replacement bulbs, the dealer charges $2-$3 each for them. I found them at Lowe's in packs of two for about a buck. They are the same bulbs used by the low-power 12v walkway lights people put in their yards so there will always be a ready source for them. They are made by "Yard Scape" and the part number is ML10WH2CYS and they are 10watt 12v just as the original bulbs are.
If the light still doesn't work when you change the bulb, make sure the wires are tight. The lights have a 2-pin wire connector about 6" above the socket for easy changes of the whole fixture. One of the wires on mine had jiggled loose just enough to cause intermittent contact. I pushed the wire back into the connector and it worked fine.
Many thanks to Fleetwood for using a common bulb and easy to work on
sockets.