We have the same issue on the fridge in our 2014 22' Sport. According to the owners manual, the frequency and duration of these beeps is meant to indicate an open door, however, the door is most definitely closed. Here is what I believe to be happening: Behind the clear plastic cover of the fridge light is a 4-wire harness that connects to the light and door switch. The door switch is electrically "open" when the door is closed, and electrically "closed" when the door is open. I believe the issue is due to condensation shorting the two door switch pins on this wire harness, tricking the control board into thinking the door is open when it is not. I believe this because when I disconnect this wire harness, the contacts on the light/switch assembly are wet with condensation. If I dry with a paper towel and re-connect, the problem goes away, but only until the condensation builds up again (couple hours if you're lucky). The only remedy I have found to make it through the night without this annoying beeping is to leave this wire harness disconnected. The only downside to this is that the interior light will not work when you open the door. Other than that, the fridge operates fine. If you really need the light, just dry the contacts and re-connect the wire harness. Kind of a pain, but the only solution I've found.
I'm curious if any others have found a better solution?