When households are said to be grounded using an earth wire, electrons are supposed to flow to the ground because the ground is at zero volts. For example, if your the live wire touches the metal casing of your toaster then the earth wire takes the current to ground. But isn't a lot of household current alternating? Therefore, how would current flow to ground because with alternating current there is no net movement of charge? With another example, what would specifically kill you if your feet were on the ground but your hands were touching an overhead cable (you would need to be tall I know). Again, no charge would flow through you specifically as it would be alternating. Would it be the ions in your body which kill you as they would be shaking back and forth due to the alternating voltage? Also, why is the ground considered to be a source or sink for electrons - wouldn't the ground have to be a conductor to have free electrons? Thank you for any help!