I wouldn't think it is the audio port as it also happens when using USB headsets. I'm thinking maybe a dock issue of some sort. Saw one person who's problem went away when they docked the switch on a different dock. Sadly I don't have that option.
My house does not have grounded plugs either, built in 1932. That product will not work for me, but I'm assuming I need some sort of grounded power strip?
Wondering if anyone can help me out here, nintendo support was no help at all. My sons switch (when docked) makes a loud buzzing noise in the background when the microphone is open while playing Fortnite. If he mutes his microphone the noise goes away, if he undocks the switch the noise goes...