There are various methods to slow and even stop visible light. Most of these methods appear to be slowing the group velocity of light, not the phase velocity. Can you slow the velocity of propagation of electricity? I have seen estimates that electricity, in a wire, propagates at 2/3 the speed of light. The drift velocity of electrons in the wire may be one meter an hour, for DC current, but I am interested in the propagation speed of the electricity instead.