Hey I to used an old deep freezer instead of a fridge, I simply bought it from MM. It just plugs into the freezer and cuts the power to it when the temperature is reached and turns it back on once it starts getting above your set temp. I got the analog one, now they even have digital ones. Never had a problem sinec installed, keeps my beer perfect temp and me happy. I actully storeded it in the same box where the freezer motor is located and just dripped a hole into the freezer for the prob. it was the only part of the wall that did not have cooling tubes in it.
http://www.micromatic.com/draft-keg-...s-cid-785.html