Magic Chef sells something that might work for you. They offer two models, one is marketed as a beverage cooler and the other is sold as a wine cooler. I measured these up early on when I was considering a kegerator/keezer and determined that 2 corny kegs would just fit if I were to cut the shelf supports. You just might be able to get a 5 gallon carboy in there.
They also come with a nifty built in temp sensor and SS edged glass door (you don't have to open it to see your brew!). I don't know what they market for, I saw a couple in the scratch and dent area of my local Home Depot a few months ago for ~$200.