Thanks for this post.
I built one using a 15 bottle wine fridge I got off Marketplace cheap. Already had the dehuey from years back. Inkbird WIFI versions were selling for 60CAD last weekend. So all in, under 200CAD, and a couple hours of my time.
My dehumidifier also had that weird third set of orange wires, it went to the PCB terminals labelled FUSE, which I assume means it's a thermal fuse, given it's embedding in the plastic shell and the look of the component.
I did modify the design slightly by mounting some 4" height adjustable legs to the fridge, to make adjusting level easier, andI removed the drip tray. With the new legs I can slide a much larger container directly under the drain hole, and it's removable for emptying.
Working beautifully with your suggested 55F setpoint, and 76%RH starting point, and slowly, ramping down.