Do you need an incubator for hatching eggs? avgfitfreak shows you how to easily make a DIY egg incubator out of an unused Monster drink refrigerator:
Since an incubator needs to be hot not cold, I installed a piece of heat tape (aka – heat mat for reptiles). This was taped onto the back wall behind the false wall (which unscrewed with a handful of screws). As a refrigerator the fan would pull air over the cool coils behind the false wall to cool the air. Now the coils were replaced with heat tape and the air will be warmed.
Who knows how hot heat tape will get if just plugged into the wall (I am sure someone does but not me)? To control how hot my incubator will get I plugged the heat tape into this thermostat I had laying around. It is designed for reptiles and has a temperature probe which I fed into the inside of the incubator.