What neutral wire means
The neutral is the wire that carries current back from the load to the panel under normal use. It is usually white and is bonded to ground only at the main service.
Also called neutral conductor, grounded conductor.
Where it matters on a electrical job
Many smart switches need a neutral at the switch box, which older houses often lack. Check before you sell the smart switch. Shared or crossed neutrals also cause AFCI and GFCI nuisance trips.
What the model code says
- The code defines the neutral conductor as the conductor connected to the system's neutral point that is intended to carry current under normal conditions. (IRC 2021, Chapter 35)
Check which code edition your building department enforces for neutral wire before you quote.
What it costs
The light switch installation cost guide has the typical job at $150 and the usual range at $100 to $200. The guide shows its sources and what moves the price.
Work it out
- Cost guide: Light switch installation cost
- Licensing: Electrical license rules by state
- Tools, templates and guides: Free electrical resources
Sources: 2021 International Residential Code, Chapter 35, Electrical Definitions (ICC). Checked October 9, 2026.