Hmm, is this the type with a dial, where you plug the fridge into the cord/socket right where you plug the controller into the outlet? The differential on this is 3.5 degrees F, so normally it shouldn't cycle on/off a lot. The only thing I can think of, is if the thermostat bulb was placed in the fridge near the blower, where the cool air enters the fridge, then it might prematurely register as cool enough, only to have the temperature equalize - and raise - shortly after the fans shut off, and then cycle on again?