Thermoplastic high-heat-resistant nylon (THHN) and thermoplastic high-heat and water-resistant nylon (THWN) building wire is a coated wire typically run through conduit or cable trays. This general purpose wire supplies an electrical current in a range of indoor wiring projects, including control circuits and appliances. It has a durable nylon jacket that resists abrasion, protects against shock, and shields the thermoplastic insulation and metal conductor from damage. THWN building wire is moisture-resistant and withstands higher temperatures than THHN building wire.

Nonmetallic sheathed (NM-B) building cable is a flexible electrical cable consisting of three or more wire conductors (including one for grounding) bundled inside a thermoplastic jacket, or sheath, that is nonconductive and heat-resistant. It's lighter than armored building cable, making it easier to handle, and its pliable sheathing is easier to unspool and straighten out. It is commonly used in residential and commercial applications to provide power for outlets, lighting, and appliances. Type NM-B cable is for enclosed, interior wiring in dry locations only (typically within a wall, ceiling, or under a floor) and should not be used outdoors or anywhere it might get wet.