I am new to cheesemaking but I wanted to make a cheese cave from a domestic fridge without touching or modifying any of the standard thermostats/wiring.
I finally found this TIMETOP 200-240V Digital Temperature Controller Thermocouple -40 °C to 120 °C with Sensor” target=”_blank”>http://www.amazon.co.uk/gp/product/B00CMA2IN8/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1 on Amazon.co.uk
This little device allows you to set a temperature and then switches the power on and off within a preset threshold of that temperature.
I wired a plug, via length of cable, to the device and then wired the output to a socket into which I plugged the fridge.
I set the temperature to 13 deg C and located the temperature sensor inside the fridge.
Bingo! The temperature is maintained between 12 degs C and 14 degs C. If I want to use another fridge I just unplug – relocate – plug in and Bingo! once again.
Of course the inside light does not come on unless the device has switched on.

I looked at these also but settled for this;

http://www.ebay.co.uk/itm/Digital-Thermostat-For-Reptile-Snake-Lizard-Heat-Mat-Lamp-Incubator-Aquarium-NEW-/301280025192?pt=AU_Pet_Supplies&hash=item4625b05a68

It’s only £7 including postage from Hong Kong. OK you need to buy some adapters for the socket and the fridge but it works a treat.

Frog