"With electricity, the overall effect from one end of a conductor to the other happens at the speed of light: a swift 186,000 miles per second!!!"

The speed of the electricity in a copper cable without insulation is 96% of the speed of light and can drop down to 66% the speed of light on a coaxial cable.

 

The key phrase,

the overall effect from one end of a conductor to the other happens at the speed of light

It doesn't invalidate this sentence, but the actual speed of an electron is much slower, inches per minute I believe.

We are talking about the electric field and the conductors response to it.