2005 NEC
404.9 Provisions for General-Use Snap Switches
(B) Grounding Snap switches, including dimmer and similar control switches, shall be effectively grounded and shall provide a means to ground metal faceplates, whether or not a metal faceplate is installed. Snap switches shall be considered effectively grounded if either of the following conditions is met: </font>
- <font size="2" face="Verdana, Helvetica, sans-serif">(1) The switch is mounted with metal screws to a metal box or to a nonmetallic box with integral means for grounding devices.</font>
- <font size="2" face="Verdana, Helvetica, sans-serif">(2) An equipment grounding conductor or equipment bonding jumper is connected to an equipment grounding termination of the snap switch.</font>
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Exception to (B): Where no grounding means exists within the snap-switch enclosure or where the wiring method does not include or provide an equipment ground, a snap switch without a grounding connection shall be permitted for replacement purposes only. A snap switch wired under the provisions of this exception and located within reach of earth, grade, conducting floors, or other conducting surfaces shall be provided with a faceplate of nonconducting, noncombustible material or shall be protected by a ground-fault circuit interrupter.
