Oh dear. You might want to brush up on your E&M physics a bit. This makes about as much sense as that one claim that if everybody jumped at the same time the Earth would move off its orbit a bit. All the modern appliances in the world won't make a lick of a difference (Even if you get the current in all of them running the same direction good luck doing that. And even if you somehow did that, the fact that it's on the surface of a sphere just makes it a crazy jumble of magnetic field lines use finger-curling if you know it. It's just a mishy-mashy mess.).
The pole-switching is really simple, actually (even for somebody like me who sucks at E&M I think I failed my AP test). The Earth's core moves and swishes and spins, thus creating an electric "current" of sorts, thus creating magnetic field. However, the Earth's core isn't a thing cylindrical rod in that case, the magnetic field would probably always stay in the same direction. Since it's spherical, it can rotate fairly easily, and in fact does so at an average of about once every 300,000 years (that's a very rough average though sometimes the spans are much shorter, sometimes much longer [the last one in recent times occurred 780,000 years ago]). It's all about the spinning core.
By the way, for what it's worth, this pole-flipping can be used to help prove evolution, but I'll leave that discussion for the Opinions board.