What is the function of a ground wire?

The ground wire serves a critical safety function in electrical systems by providing a safe path for electricity to escape in the event of a fault. This fault may occur due to various reasons, such as a short circuit or equipment malfunction, which can lead to excess current flow. If the ground wire is properly connected, any excess electrical current will travel through it instead of passing through a person or causing damage to the electrical system. This minimizes the risk of electric shock and helps prevent electrical fires, making the ground wire an essential safety feature in residential electrical systems.

The other options do not align with the primary purpose of a ground wire, which focuses solely on safety and fault mitigation rather than enhancing current flow, controlling voltage levels, or connecting the electrical panel to the grid.