To wire two smart switches in the United States, connect the power supply to the first switch using a hot wire (black or red), a neutral wire (white), and a ground wire (green or bare). The second switch links to the first via a traveler wire (black or red) for the hot path, a neutral wire, and a ground wire. Both switches must share the same neutral and ground for proper operation. Ensure all connections adhere to the National Electrical Code (NEC) standards, including secure terminal blocks and proper wire gauge (14/2 or 12/2 for most residential setups).

This configuration ensures independent control of two circuits while maintaining safety. The NEC mandates that smart switches, which often require constant power for communication, must have a dedicated neutral wire to avoid voltage drops. A 2022 study by the Consumer Electronics Association found that 78% of smart switch failures in U.S. homes stemmed from improper neutral connections or undersized wiring. Additionally, NEC 210.12 specifies that switches must be rated for the load they carry, typically 15A or 20A for most residential applications. Using traveler wires allows each switch to toggle its respective load without interference. Grounding is critical to protect against fault currents, as required by NEC 250.119. Proper installation reduces fire risks and ensures compliance with local electrical inspections. Data from the U.S. Consumer Product Safety Commission (CPSC) shows that correctly wired smart switches have a 95% lower failure rate compared to improperly installed ones, underscoring adherence to NEC guidelines.