While untrained people can safely perform some electrical tasks, a number of jobs come with significant risks and are best left to professionals. Changing a light bulb, for example, is generally safe, while rewiring an electrical panel is potentially deadly for those who lack proper training.
The risk of electrocution is high when working with live wires, so professional electricians undergo extensive training. When working near electrical wires, experts recommend assuming any nearby wire is live. Electrocution is not the only risk; annually, tens of thousands of fires start due to home electrical systems, and people lacking experience are more likely to make mistakes that lead to potentially deadly house fires.