** do I have a malfunctioning (defective) wall tap, or is there something wrong with the outlet that caused this? **
I don't know what a "wall tap" is but if you're referring to the wall "outlet" (the thing you plug cords into), it should likely replaced and also anything that was plugged into it. If you plugged a new thing into a bad outlet, there's a good chance it may now be damaged too.
The wiring to the outlet should likely also be inspected, preferably by a licenced electrician to ensure there is not going to be any chance of fires. Don't scrimp on safety!