In a residential setting, which type of conductor is most commonly used for lighting circuits?

In residential settings, the most commonly used conductor for lighting circuits is NM cable, also known as non-metallic sheathed cable. This type of cable is favored because it is lightweight, easy to work with, and cost-effective. NM cable is made up of multiple conductors insulated with or encased in a non-metallic sheath, which protects the wiring while ensuring safety.

NM cable is particularly beneficial for residential applications, as it can be routed easily within walls and ceilings, making it ideal for lighting installation. It is typically used in dry locations and is suitable for various types of residential electrical work, including branch circuits that supply power to lighting fixtures.

While other types of conductors, such as THWN conductors, are used in specific applications, they are not as versatile for typical residential lighting. Similarly, although Romex cable and flexible conduit might seem like good options, Romex is actually another colloquial name for NM cable and flexible conduit is not as commonly used for standard lighting circuits due to its more specialized nature and installation requirements. Thus, NM cable stands out as the standard choice for residential lighting circuits.