But it's teh coolzor, omg!
Beer's right. Any way of doing it would be inefficient.
Some form of laser would be the best way, if there was a practical way for it.
or. Have no wireless electricity? I mean, in the future, we could have a mini fusion generator in our houses. It would be cool if we found a planet made up of 'white gold'. ( Because note that White Golds have no resistance to electricity ). we'll eat that planet right away from its orbit around its sun.
Although it would be efficient, if we fill plasma inside the magnetic field tube, the electricity wouldn't have to travel air. it would travel Plasma. Electricity travels plasma very good without major loss. Also, those conduits could be high up in the air, interlooping a city, creating something like a shield, and also could be redirected as a super-charged plasma. XD ( Magnetic Fields can either contain plasma or repel them. )
Technically this isn't a wire. But i guess you could call it a conduit.
You could actually go through that thing. But after you go through it, you probably won't exist anymore but as a burned up dust, however with enough magnetic field density, not a electron particle would be released.