Cheap parts, and shortcuts.
@Ben8257 can explain better, but instead of wrapping the wire around the screws, they pushed them in the holes. In the end, it causes an arc, and blows the switch. How can you tell? Well, they just stop working.
In the pictures, you can see remnants of the copper wire still in the little holes in the back. I had to strip more of the wire to wrap them around the screws/poles correctly.
As I told Mark earlier, unfortunately "stab in" receptacles are completely legal... and also cause 80 - 90% of electrical house fire issues. It is the quick and easy way to "get the job done" and unfortunately 10 - 15 years later (typically) becomes a royal pain in the butt for home owners!
Whilst these can be found in many of our homes, especially by what we all know as "speed builders" as opposed to custom homes, these electrical contractors get paid by the square foot and are trained to work legally but barely legally.
Anyways the first place you will notice issues are on receptacles on exterior walls typically as these walls heat and contract many times throughout the year as opposed to.interior walls that are conditioned. These stab in receptacles utilize a spring to hold the copper condu tor in contact with the brass plate on the plug. This spring wears over time and becomes loose allowing and acr, typically on the Neutral (white) side of the plug. The neutral.carries the unbalanced load and creates a hot spot... I have seen it many times where the insulation is melted off of the copper and sometimes even burns a hole in the plastic boxes in the walls.
If anyone starts having issues with plugs not working or intermittently working, often you can hear weird pop sounds... just pull a plug out of the wall, likely the contractor utilized "stab in" receptacles, and unfortunately I highly recommend getting every single one of them out of your house as they are NOT safe!
It only takes a few minutes each to swap them out and wire them properly once you get the hang of it.
Remember do not be afraid of electricity, respect it!
Not that is has anything to do with poker chips but if anyone would like help or a walk through on how to check your plugs feel free to shoot me a PM, I'll shoot you my # and will happily help walk you through any electrical questions. After all we all have something we specialize in and I am.happy to help, especially on safety issues!
This one could save you and your families lives, we all joke about things but look at
@krafticus receptacles, it's not funny.