Which situation is most likely to require a GFCI for safety?

Operating outdoor tools near water is the most likely situation to require a Ground Fault Circuit Interrupter (GFCI) for safety. GFCIs are designed to protect individuals from electric shock by quickly shutting off power when a ground fault is detected—especially important in environments where moisture is present, as water can significantly increase the risk of electrical shock.

Outdoor tools, when used near water sources such as pools, ponds, or during wet conditions, have a higher likelihood of an electrical fault due to the proximity of water. The ability of GFCIs to detect these faults and react promptly helps to ensure safety for the user, making their presence essential in such scenarios.

In contrast, fixed circuit wiring typically involves installations that are less exposed to water. Indoor lighting systems that do not interact with water are generally considered safe without GFCIs, and scenarios demanding heavy electrical loads may require different safety measures but are not specifically related to ground fault protection. Thus, the presence of water when operating outdoor tools makes the need for a GFCI crucial for minimizing the risk of electrical accidents.