A household refer has a small fan to blow air across the condensor coils. They can be as cheap as 20 bucks, or up to around 100 or so in the built in expenso models. I have seen these fans windings go bad before and cause a ground fault condition on the fridge frame. The reason I mentioned cost of fans is the cheap ones seem to be worse about this. Another thing to do when checking a fridge is shine a light in the dark spots under, or behind. Mouse droppings are sometimes a good sign leading to finding chewed up power cords, and appliance wiring.
