Birds and squirrels don't get electrocuted on a bare live overhead wire because they're not touching the ground, nor are they in contact with an object on the ground. However, if you were to touch an electric wire while standing on the ground, on a ladder or on a roof, you could suffer an electric shock.

Electricity would pass through your body on its way to the ground. Even an insulated conductor can present a risk because birds and squirrels can peck and gnaw at its sheath, allowing electricity to flow towards the ground ... through the person or animal that receives the shock.