If a pet turtle is put in the refrigerator will it hibernate?

Actually, if the conditions are right, it will. The problem is, what if you lose power and the fridge goes off? What if there is a problem with the fridge and it seems to be working on the outside, but is actually not cold enough on the inside, or becomes dangerously cold? Your turtle could either awaken from its hibernation locked in a fridge with no food or escape, or would die from freezing.

All and all, do not put your turtle in a fridge. The turtle gets no physical benefits from hibernation, and it is far too risky.