UPDATE. Found the problem which is perplexing. The other light fixture on that curcuit identicle to the one with the burnt bulb had a different light bulb in it. It was a single contact bulb in a double pole light fixture. I replaced that bulb with a double contact bulb (1076) and it quit burning fuses. Now, that single contact bulb has been in the fixture since it was new. How did it work without burning fuses to this point, I do not know.
2012 Crusader 320RLT
2011 F250 Lariat 6.7L
2016 (19 Nights Camped/1348 Miles)
2015 (38 Nights Camped/3560 Miles)
2014 (28 Nights Camped/1980 Miles)
2013 (30 Nights Camped/1411 Miles)