For those who think removing the light bulb solves the problem, unless your refrigerator is not self-defrosting, you’re probably wrong. The switch typically has an effect on the defrost circuit. This is independent of the thermostat problem mentioned by gadolhadorah. Also, it’s not a good idea to leave the switch taped all the time. We had a refrigerator that stopped working if we taped the switch for even a three day Yom Tov. A repairman told me that that was a problem with that brand and recommended a different brand.
You can read about adaptive defrost controls in Rabbi Hoffman’s article referenced above.
After running out of good quality duct tape (the cheap stuff is useless), I came up with a solution using a wide craft stick (i.e. a tongue depressor) and sticky velcro.