Grounding switches and metal cover plates
Light switches, dimmers and control switches must connect to an equipment grounding conductor and allow a metal faceplate to be bonded. Where a switch box has no ground, a narrow exception applies to replacement switches.
What the code requires
Snap switches, dimmers and control switches must be connected to an equipment grounding conductor. They must provide a way to bond a metal faceplate, whether or not a metal plate is installed, and any metal faceplate must be bonded.
Two methods are allowed. Metal mounting screws can connect the switch to a grounded metal box or cover, or to a nonmetallic box with a built-in grounding means. Or an equipment grounding conductor or bonding jumper can be connected to the switch's grounding terminal.
On the job
- In older homes without a ground wire, metal plates on new switches without GFCI protection are a common correction.
- Smart switches with the green grounding lead left unconnected are another frequent problem.

Exceptions that matter
- Replacement only, with no ground in the box: a switch within 8 ft (2.5 m) vertically or 5 ft (1.5 m) horizontally of ground or grounded metal needs a nonconducting, noncombustible faceplate with nonmetallic screws, unless the yoke is nonmetallic or the circuit is GFCI-protected.
- Listed kits that meet specific nonmetallic conditions.
- Snap switches with integral nonmetallic enclosures under 300.15(E).
Related sections
- NEC 250.148
- NEC 406.4(D): Replacing receptacles: GFCI, AFCI and TR rules
- NEC 404.22
- NEC 404.2(C): Neutral wire required at light switches
Where this comes from
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Kyle Robert Anderson KBC Electric · CSLB #1073066 · C-10 Electrical · Licensed since 2021