I used the STC-1000 direct wire in my incubator. It powers up a receptacle, into which my ceramic emitter is plugged in. It works flawlessly.
I switched my LGs to use the STC-1000 last year after I had to watch the temp 24/7 with the knob style LG controller. I wired it up inside a duplex wall box and wired it to a receptacle.
Sorry, but I have better things to do that watch thermometers and worry if the room warms up! My home built incubator has been hands off since I started it, other than adding water to the tray.
The digital reptile ones are already built. You plug it into power, plug your heater into it, and put the probe in the incubator. Once calibrated, it should hold steady heat. There are a number of different models, different temp swing range, so shop around if going this route.