If you have the remote for levelers, slides, etc it probably has a button for that light. Our 351 does.
If you have one check the bulb first. The switch will be spring loaded (returns to the center position when released), porch light should be the same. The switch will activate a relay on the control panel for all the wireless "stuff" so it could be a bad relay or even something amiss in the panel.
2013 F-350 CC SB 2WD 6.7PS
2013 Eagle Premier 351 RLTS
-SOLD- 2012 X23B
-SOLD- 2003 Ford Expedition 5.4, Bilstein shocks