Even if you do, you won't have a problem in the computer. It will be warmer than the refrigerator so any dew activity will be elsewhere.

Getting the power cord in will require some creativity.

And frankly, I have no idea if a small refrigerator can keep up with the heat output of a small computer. It would be an interesting duel.

Most fridges have a temperature adjustment, and the machine is generating heat. Throw a temperature monitor in the fridge and keep it above the dew point, and you won't have any condensation.

http://www.decatur.de/javascript/dew/index.html