Built an incubator today based on Miss Prissy's plans. Everything is wired correctly, the thermostat works except one thing--currently I am having 15 degree temp swings! The thermostat I am using is the cheap-o hot water heater thermostat I see everyone else using. I put it in an electrical box like many more recent posts have advised. I have a very nice three speed computer fan installed. I have tried with both a 20 watt and a 60 watt bulb now, with the same results. Please help!! I am so frustrated now I want to cry. Currently the thermostat is about 7 inches from the light source--will moving this change my results? Should I take it off of the metal electrical box and use the air temp? Is there an alternate thermostate I could use? Can somebody please tell me what else I can change without spending a ton more money--i have already put $60 into this project, which I really should have used to fix up our old hen house instead. Help please from all you do-it-your-selfers out there!!!!