Use a copper, solid, insulated pigtail wire that matches the circuit's gauge—14 AWG for 15-amp circuits and 12 AWG for 20-amp circuits.

Wire Type and Gauge

For standard residential switches, the pigtail should be solid copper wire with insulation suitable for indoor use, such as THHN or NM-B (Romex) if running through walls . The gauge must match the existing circuit: use 14 AWG for 15-amp breakers and 12 AWG for 20-amp breakers . Using a smaller gauge than the circuit can cause overheating and is unsafe.

Insulation and Color Coding

• Hot wires: black or red insulation
• Neutral wires: white insulation
• Ground wires: green or bare copper Insulated pigtails are recommended for accessible areas to prevent accidental contact, while bare copper is only used for dedicated grounding paths .

Pigtail Length and Installation

Cut the pigtail to 6–8 inches, providing enough slack to work comfortably outside the electrical box . Strip about ¾ inch of insulation from the end of the pigtail and the existing wires. Twist the wires together using lineman's pliers and secure them with an appropriately sized wire nut or push-in connector . This ensures a strong mechanical bond and maintains circuit integrity.

Connector Considerations

Pigtail connectors can be twist-on, lever-style, or crimped, depending on preference and accessibility . Twist-on and lever-style connectors are reusable if undamaged, while crimped connectors are generally permanent. Always ensure the connector accommodates the total number and gauge of wires in the splice.

Summary

To safely connect a switch:

1. Match the wire gauge to the circuit (14 AWG for 15A, 12 AWG for 20A).
2. Use solid copper, insulated wire.
3. Follow color coding for hot, neutral, and ground.
4. Cut pigtails to 6–8 inches and strip ¾ inch of insulation.
5. Twist wires together and secure with a proper connector. Following these guidelines ensures a safe, code-compliant, and reliable connection for your switch installation .