[mnw21cam]

The air inside a fridge is really dry, simply because it is cold, but also because the heat exchanger inside has to be even colder in order to keep the fridge cold, and so all the condensation occurs on that. If you put a warm laptop inside a fridge, any moisture in the laptop will be sucked out by the dry fridge air and condensed on the fridge's heat exchanger.

However, it's when you take your cold laptop out of the fridge that it may get problems with moisture. If your laptop is colder than the dew point of the air, then the moisture will condense on it. To solve that, put the laptop into a sealed plastic bag while it warms up to stop the moist air getting to it (although this may be incompatible with actually running the laptop).