Author here. Unfortunately after removing the wall switch, I found a newly installed mini-fridge would cause signal dropouts sometimes when the motor started or stopped. Moving it into an adjacent room reduced the frequency of dropouts, but I still got them periodically (and can no longer hear the mini-fridge to tell if dropouts are correlated). A few weeks ago I unplugged the mini-fridge because I barely used it and it had filled with ice. Since then I have not gotten any dropouts (aside from static shocks in my room), but haven't played my Wii long enough to know with confidence it won't happen again.
I don't have any power isolators, UPSes, or similar. My first thought was to swap the power supply or console, but I don't have an easy way to do either one without paying for one-time components I won't have a good use for afterwards (I could sell a Wii on eBay, but have never sold there before).
