Which type of wire is commonly used for residential light fixtures?

Type NM cable, often referred to as non-metallic sheathed cable, is the most common wiring used for residential light fixtures and general light branch circuits. This type of cable is designed specifically for indoor residential use. It consists of two or more insulated conductors, typically made of copper, and is sheathed in a protective plastic covering that provides both insulation and protection from physical damage.

NM cable is favored for its flexibility and ease of installation in walls and ceilings, making it ideal for residential applications where the wiring may need to be routed through various areas of a house. It is suitable for dry locations and is often used for feeding light fixtures, receptacles, and other household circuits.

The other types of cable listed serve different purposes. Type THHN wire, for instance, is used primarily in commercial and industrial settings and is not typically suitable for the same applications found in residential settings. Type UF cable is designed for underground use and is more suited for outdoor applications, while Type SE cable is utilized for service entrance applications and is intended for overhead or underground service feeds coming into a building. Therefore, NM cable stands out as the most appropriate choice for wiring residential light fixtures.