The Wii U does use a power brick.
A badly designed power brick can and frequently will trip breakers/RCDs, throw loads of noise onto the circuit and otherwise mess with things.
Many cheap Chinese third party replacement supplies of any form are atrociously designed; pick an electronics forum, discussion place for electronics, electronics youtube channel... and you will find people pulling apart power supplies, USB chargers and all the rest for very good reason.
Short version yes it is a very real thing. Junk the one you have and buy a new one, preferably original or good third party (assuming such a thing exists). I don't know if the wii u had different models of supply offhand (the 360 did and a few other things have done that over the years) so you might want to check for that. If you were or know someone that is into electronics there might be some stuff you can do, I certainly would not suggest you buy something to try to negate it if for no other reason than something that badly designed in the first place is probably not going to be great for your wii u.