Final answer:
Grounded distribution wiring was introduced to residential electrical systems in the 1960s, enhancing the safety of home construction by preventing electric shocks and reducing fire risks.
Step-by-step explanation:
The subject of the question is based on the historical development of electrical systems in residential buildings. More specifically, it refers to when grounded distribution wiring, which is an important safety feature in electrical systems, was introduced into home construction. This innovation is a critical part of ensuring that residential electrical systems are safe for inhabitants by providing a path for electrical current to safely ground in the event of a fault. Grounded systems became a standard part of electrical codes in the United States in the 1960s, considerably improving the safety of residential electrical systems. As a safety measure, grounding helps prevent electric shock and can reduce the risk of electrical fires.