I have a Johnson Controls Refrigerator Thermostat. Plug the appliance of your choice into the thermostat, then plug the thermostat into a standard 120V outlet. An analog dial lets you set the setpoint temperature between 30 and 80°F, with 1 degree increments. The Johnson Control thermostat has a 3 1/2 degree differential, which means that the thermostat will shut the fridge or freezer off (stop cooling) at 3 1/2 deg below the setpoint and start the unit (resume cooling) once internal air temperature exceeds the setpoint
$40 shipped and its yours.