How do you know if the light in the refigerator goes out when you close the door?

On our refrigerator, if you close the door slowly, you can see the light go out just before the door closes.

Depress the light switch, located usually around the inside parameter of the unit. If the light goes out, rest assure, the light turns off when you close the door. If you constantly need to keep checking to ease your worry, you may have a mild form of {insert mental health issue here}.

Set a digital camera for 10 seconds, close the door, and wait 20 seconds, open the door ,and check the picture you just took. If your joking, it's not too funny. If you are not joking, find another way to use your time and mine with something that really helps unfortunate people or animals. :-) 

The light in the closed refrigerator is one of the facts of science and mechanical engineering that you must take on faith.  Like all truth, it is rooted in faith hence valid even when pseudoscientific atheists persecute you on their arbitrary nonsense for telling the truth.

We mount a normally open switch in the door, which disconnects the power from the light when we close the door.  Press the switch and the light goes out.  Release thew switch and the light turns on.  Faith confirms that the light is out when the door is closed.

We have faith that the light is out when we close the door because science, and engineering, say that it is so.  So does your experiment.

Science always confirms faith, to the letter.  That, dear folks is true science.  Atheist pseudoscientists need not apply because atheism is always wrong as are all its misguided cultists.