I'd like to set the thermostat on my 18 cubic ft refrigerator
so that it runs the food compartment at about 66F so that I
can use it to ferment Mead and Beer.

I have a Ronco controller on my chest freezer so that it stays
at 52F for my beer kegs. I'd rather not use an external
controller on the refrigerator because it would make the freezer
compartment useless.

Any ideas or place to look for modifying the thermostat?

Dick