Identify one safety device used in electrical installations.

The Ground Fault Circuit Interrupter (GFCI) is a crucial safety device used in electrical installations to protect individuals from electric shock. It operates by monitoring the flow of electricity in a circuit and can detect an imbalance in the electrical current. When it senses that the current is leaking through an unintended path, such as through water or a person, it interrupts the circuit almost instantaneously, reducing the risk of serious injury or fatality.

GFCIs are especially important in wet or damp locations, such as bathrooms, kitchens, and outdoor areas, where the risk of electric shock is heightened. By providing this level of protection, GFCIs enhance the overall safety of electrical installations and help prevent electrical accidents.

In contrast to other choices, while transformers, fuses, and voltage regulators have their specific functions in electrical systems, they do not directly serve the primary purpose of protection against electric shock. Transformers are used for changing voltage levels, fuses provide overload protection by breaking the circuit when there is too much current, and voltage regulators maintain a steady voltage. None of these devices are designed specifically to cut off the electrical flow in response to ground faults, which is the defining characteristic of a GFCI.