What must be done before beginning any electrical work?

Before beginning any electrical work, ensuring the power is turned off is crucial for a safe working environment. This step is fundamental to prevent electrical shock, which can lead to serious injury or even fatality. De-energizing the circuit protects not just the individual performing the work but also helps prevent damage to electrical components and tools.

Checking circuit breakers, verifying tool functionality, and confirming voltage levels are all important procedures that can be performed after confirming that the power is safely off. While these steps are necessary for ensuring everything is safe and functional, they do not take precedence over the critical step of de-energizing the circuit, which is essential to actual safety during electrical work. Thus, turning off the power must always come first.