THE RADIO (AND CAMERA SYSTEM) HAD BEEN ACTING STRANGELY AND MY CIGARETTE OUTLETS STOPPED WORKING WHILE I WAS DRIVING. I STOPPED FOR THE NIGHT AND HAD PARKED AND CONNECTED THE RV TO THE CAMPGROUND POWER. ABOUT 10 MINUTES AFTER PARKING AND HOOKING UP I STARTED TROUBLE SHOOTING THE LOSS OF POWER TO THE CIGARETTE LIGHTERS. I CHECKED THE FUSE AND DID NOT SEE ANY VISIBLE FAILURE OF THE FUSE BUT DECIDED TO TRY A BRAND NEW FUSE JUST IN CASE. AFTER REPLACING THE FUSE FOR THE CIGARETTE LIGHTERS, A FIRE STARTED IN THE AREA OF THE RADIO AND CIGARETTE LIGHTERS. WHILE TRYING TO USE A FIRE EXTINGUISHER TO PUT OUT THE FIRE BY SPRAYING UP FROM UNDER THE DASH, THE RADIO FELL INTO THE DASH. I THEN SPRAYED WHAT WAS LEFT OF THE FIRE EXTINGUISHER INTO THE RADIO OPENING. I WAS UNABLE TO PUT THE FIRE OUT AS I NOTICED A GLOW IN THE DASH STILL TO THE DRIVERS SIDE OF THE RADIO OPENING. AT THAT POINT I EVACUATED THE RV AND CALLED 911. THE RV BURNED DOWN AND IS A TOTAL LOSS.