freezer compartment (unused) mold in fermentation fridge

I have a spare refrigerator in my garage that I use as my fermentation\bottle conditioning chamber. It is an over\under (fridge\freezer) model that has a STC-1000 temp controller on it. I only use the fridge part of the unit for my ferm chamber and don’t use the freezer part at all. I have been using it since May of this year and I have noticed there is an accumulation of water in the bottom of freezer compartment which is contributing to mold beginning to appear on the inside of the freezer.

Should I be concerned about this? Should I mix up some bleach solution to spray it down and clean it? how do i keep this from happening?

Try to clean it up. While I'm not using my chamber (after the first week of fermentation), I leave the doors open. Helps stop the nasties.

Wire the fan in the frezzer to run off the heat setting on STC- 1000 controller to circulate the air should help cut down on trapped air condensing.

Good idea beaksnbeer. So basically the evaporator fan will circle warm air into freezer to dry moisture. I will have to look into that.