Stress
Working with electricity is stressful. A lapse in judgment puts you in major danger, which is why it's best to follow the National Electrical Code at all times. You may be working on the Next Great American Electrical Code in your spare time, but until that gets picked up as the industry standard, stick to the rules.
A lot of what an electrician does is troubleshoot problems. Being a good problem solver alleviates stressful work environments. You don't want the stress of working with technical problems to influence your judgment while working with electricity.
Also, some companies hire electricians to fill around-the-clock shifts, meaning you may be working more hours during the night than during the day. It's going to be tough keeping that werewolf secret to yourself much longer.
Self-employed electricians may have to answer late night calls for their clients. While most electricians work regular hours, starting out or maintaining your own company could have you out of the house fifty-plus hours a week.