Light and Fan in mini fridge incubator?

I am working on making a mini fridge into an incubator. Diamensions are roughly 32"T x 18 1/2" w x 16" Long. My questions are:
1.) Do you need a flourescent light in there? If yes why? And if yes do you have it on all the time or do you put it on a timer?
2.) Do I need a fan in this incubator (I keep reading that fans are not needed in smaller incubators). If it is better to have a fan in there where is the best place to put it (ie: in the center at the top, in one of the four top coners, on the bottom somewhere). Is it better to have more then one fan in there?
Thank you!!!