It's not a scam. We got the same notice for our 01 Adventurer on the Ford F53 Chassis. As I remember it wasn't a NHTSA recall, but part of a voluntary one by Ford. Apparently the bulbs were missing or improperly installed in some of the dash modules.
It's the same light that illuminates when the parking brake is engaged. If it contunues to remain illuminated after the parking brake is released (and the parking brake switch is properly adjusted) it's an indication that the brake fluid reservoir is low.
If your parking brake light works obviously the bulb has been installed.
We got several notices. I finally called our local dealer and explained the light was working properly. They asked me to bring in the coach so they could verify it was working and remove us from the list. It took the tech all of 30 seconds to see all was well. He signed off and no more notices and no attempt to sell anything.
2013 Adventurer 32H