> With electricity the electromagnetic wave wouldn't exist without the electron current flowing in the conductor

So where is the conductor between the sun and your eyeball? Or for that matter between the TV transmitter and your TV set etc. etc.

The electromagnetic field requires no conductor at all. In fact it requires absolutely nothing - not even the "luminiferous ether" should you be fond of googling.

If you read the quote again, I specifically said "with electricity" you need the electron current. Clearly your examples of light travelling and radio waves are not forms of electricity. They're all electromagnetic waves, but they are initiated in different ways (although not fundamentally different - they're all produced by moving charged particles in one way or another).

Electricity is essentially an electromagnetic wave travelling outside and in parallel with two (or more) conductors, created by a combination of movement of electric charge along the conductors together with an electric potential difference between the conductors. The point I was making is that the electrical energy (ie: the phone or ADSL signal in the phone line case) is carried by the wave outside the conductors, not by the electrons (or anything else) within the conductors. The signal is therefore travelling through the materials around the conductors, and so these materials influence the communication of the signal (in particular the propagation speed).