Edit: There was an error in the schematic in original post. Here’s the corrected version.
The original digital controller for the Grainfather Conical Fermenter had a monochrome screen and pogo pins at the back. The pogo pins were the downfall of that box due to their unreliability. It was was upgraded to a newer version a few years ago with a color screen and Wi_Fi. If you upgraded and still have the old controller sitting around somewhere, here is what you can do to mod it to control a fridge/freezer. I could have just used an STC-1000 but this controller has a few nice features that the STC does not have.
https://cdn.homebrewtalk.com/data/attach/779/779690-Grainfather-controller-project.pdf
Cool. I’ve got a few of those sitting around.