Looks like the author of those videos has a serious issue with his house wiring. I've done some simple tests with a multimeter out of curiosity in my house, looking for stray voltage, but I've found none outside of expected voltage picked up when close to outlets, lamps, clock radios, etc. My house is less than 10 years old, and has the electrical system grounded to the rebar in the concrete footing. When I'm grounded to my house electrical ground or the copper plumbing, the voltage impinging on my body drops.
I've used both the electrical ground and copper pipe to get my electrons. Getting a wire out of my 2nd story bedroom and into a ground stake is more than I'm interested in taking on right now, and i don't see a real need to improve based on my measurements. I'd suggest if you're concerned, get a multimeter (mine was relatively expensive, but I'm an electrical engineer - you can find one for maybe $30-40US) and take some measurements.