Is it damaging to turn off a small fridge for two days every week?
Someone will close the door and...



It will fill the fridge's internal spaces with mold

Air holds moisture.  Warm air is capable of holding more moisture than cold air.  Everytime you open the fridge door, you let in room air.  This contains more moisture than air can possibly hold at refrigerator temperatures, which means condensation occurs inside the fridge.  When it occurs on the coils, it is visible as frost.  

Those panels that line the fridge interior are not airtight.  Air also circulates behind them and condenses there.  

The upshot is, a fridge has a lot of water or ice inside it, in all sorts of inaccessible nooks and crannies.  When you shut off, the interior warms to room temperature, a sealed space with more condensed water than the air can possibly hold. It hits 100% humidity and you have a petri dish for mold. 

The only cure is to leave the door open enough that air circulates freely, which keeps the humidity same as ambient.  However, this doesn't work. Humans have embedded programming to close any refrigerator door on sight. The entire species has 18 years of full-immersion psychological conditioning starting nearly from birth to close refrigerator doors. 

Why the mold is bad

I learned this by repeatedly cleaning mold off a fridge we ran when needed.  It seems a simple fix; clean off the surfaces and you're all good.  However, those are not the only surfaces. There is also the backside of those surfaces, the machinery including evaporator coil, and electricals.  You cannot reach those to clean them.  And to be clear, the interior lining of fridges are decorative, not hermetic seals.

Exactly the same black mess is happening in  the inaccessible locations, in roughly same proportion, since the humid air is convecting all over the fridge.  If it happens repeatedly, the mold gets thicker since you're not cleaning it. 

Obviously that can affect machinery, but this reserve of mold spores can also get on food.