Following the theme of falling tree in the woods making a noise I would like to introduce the new theme of 1.001 useful things you can do with a Smartphone.
You can answer one of the most important questions in the Universe.
Get your 12 year old sibliing (they will have an iPhone if you had not noticed) to bring a friend of theirs over (they will also have an iPhone).
Ask them to use "facetime" (they will understand don't worry) to call each other. Get the pictures running so they can see each other.
Now open the fridge and place one inside. Close the door.
Assuming you have good reception in your area (fridge being a metal cage which is not so good for radio waves in case you missed it in Physics) you will now be able to see if the fridge light does indeed turn off when the door closes ?
Graham
The low tech model for this involves taking everything out and simply fitting the 12 year old in the fridge for a short period.