Mr. Grumpy Pants wrote:
You could have a leaky door gasket. If you have an icemaker there could
be issues because of that also, but I bet its the gasket. Door gaskets
aren't the easiest fix usually. They often involve removing the liner
and if you don't seat them just right you will still have the same
problem. You might want to consider hiring a repairman. I would.

Good luck-
GP



Definitely check that the door is sealing correctly. A 3yr old frig
shouldn't have a bad gasket, but it could also happen from something
being slightly in the way so the door does not close completely. If
it's not that, then something is likely wrong with the defroster, which
is essentially a small heater that comes on periodically to melt the
ice on the evaporator.