Incubator light won't turn off, buzzing

[lecobb]

I set up my incubator (gopherbator plans), and am almost through my first hatch (putting the eggs in the hatcher tomorrow). My light has stopped turning off, and instead dims and buzzes. When it's on, it functions fine. I've tried a new lightbulb, which didn't make a difference, and I redid the wire connections to the light and the thermostat. It's still functioning, but getting on the hotter side (since the light won't turn all the way off), and the buzzing is obnoxious. Any ideas?

 

[Pocket Money Poultry Farm]

Mine did the same thing. I plugged my light into an outlet that is controlled by a light dimmer switch. I was using a 60 watt bulb and with the switch I dimmed it down to what I’m guessing was about 50 watts. The light started cycling back on & off and held a steady temperature