Electrons pass a pulse of energy along a cable at the speed of light in the insulator between the two conductors. Few people look at the problem of how information about the insulator flows into the electron. The problem is conventionally explained akin to a line of touching ball bearings in a wire, you push the end one and almost immediately the one at the other end moves. This model works when you forget about the speed of electricity, but then fails to account for the effect of the insulator on the speed.
Critically, when you consider a capacitor charging up, you find that the light speed energy flooding across the plates causes discrete, step-wise voltage increases when it reflects back at the far end of the plate and adds to further incoming energy. The issue here is that Maxwell’s special equation is based on the model of the capacitor charging up continuously, giving classical EM. When you take account of the stepwise increases which occur, you start to get a picture which looks more compatible with the view of quantum mechanics than Maxwell’s original theory. See curve at: http://www.ivorcatt.org/icrwiworld78dec2.htm