A good friend of mine once remodeled an entire house by himself, including re-wiring much of it. I told him how amazed I was that he did the electrical work because I wouldn't have a clue what to do. He told me that wiring was easy. My response was that I never know what to do with the ground wires. "Oh, that's not a problem," he said. "I just snip those all off because they don't do anything anyway."
Remind me to never buy a house from him.
Anyway, did you ever wonder how birds or squirrels can sit on high voltage power lines without being hurt? I have. Link here for the answer.