Yesterday when I unplugged my GamePad AC adapter from the wall socket, the socket sparked and caused a short circuit. This is the first time any charger for any product of mine has ever done this. While the socket is pretty old, it is normally in fine condition, and like I said, this has never happened to me before. After reading up on short circuits, I discovered that one of the big causes is the plug getting too hot and melting away the insulation. Before, I've noticed that after a few hours, the AC adapter plug gets too hot to touch- I could only touch the outside for a few seconds before I got burned. All my other chargers (including the DS and 3DS chargers) just get a bit warm, but never too hot to touch. Basically, I think the adapter getting too hot melted away the insulation in the socket and caused a short circuit.
If this is the case, is it a defect in my particular AC adapter, or a problem in all GamePad AC adapters? Are there any steps that I can take to prevent the plug from overheating and causing more short circuits? If it's relevent at all, the AC adapter is the one that came with the Deluxe set, which I got in 2012. It was plugged into the charging cradle with the GamePad on the cradle at the time when I unplugged the adapter and caused the short circuit, but I've done the exact same thing with the GamePad and the 3DS multiple times and nothing happended until today.