In MAKE, Vol. 4, Mister Jalopy wrote a "Maker's Bill of Rights." In the introduction, he stated "If you can't open it, you don't own it."
Well, here's a light switch that I paid full price for, but don't really own. I learned this when the block plastic strap (the part attached to the chain you pull to turn the light off and on) broke off inside the housing. There was a screw on the housing, but when I removed it, the housing wouldn't come apart. That's because the metal socket (the part with the threads in it) has a dimple pressed into it, preventing its removal from the plastic housing.
In addition, the seam between the two halves of the plastic housing seem to be glued or melted together, violating one of Mr. Jalopy's tenets: "Screws better than glues."
So I had to throw it away instead of repairing it. Yes, I know it's dangerous to play with electricity, but I would have liked to have been able to peek inside, at least!
Here's an attractive PDF version of the Maker's Bill of Rights.