If you are searching for wiring 2 way light switch, you are likely outside North America (where it is called a 3-way switch) or using older electrical terminology. In the UK, Australia, and New Zealand, a "2-way switch" controls a single light fixture from two different locations. In the US and Canada (under the NEC), this exact same circuit is called a 3-way switch. A standard US single-pole on/off switch is technically a "2-way" device (two terminals), but no one searches this term for a basic single switch.

This guide provides the direct, decision-forward procedure for wiring a dual-location lighting circuit. The direct answer: To control one light from two locations, use two 15A 3-way switches (US) or 2-way switches (UK/AU) wired with 14 AWG (1.5mm²) copper cable. In the US, you must use 14/2 NM-B for the line/load and 14/3 NM-B for the traveler strappers.

The Terminology & Decision Path

Before stripping a single wire, you must identify your regional standard and load requirements. Mixing US and UK wiring methods is a fast track to a short circuit. Use this decision table to lock in your exact materials.

Criterion US / Canada (NEC) UK / AU / NZ (IEC/AS)
Switch Name 3-Way Switch 2-Way Switch
Terminals Common (Black), Travelers (Brass x2), Ground COM, L1, L2, Earth
Cable Type 14/2 NM-B & 14/3 NM-B 1.5mm² Twin & Earth + 3-Core
Standard Lighting Load 15A Circuit (120V) 6A/10A MCB (230V)
Concrete Default Pick (US): Stop guessing. Buy two Leviton 5603-2W (15A, 120V/277V AC 3-way switches), one roll of Southwire 14/2 NM-B, and one roll of Southwire 14/3 NM-B. For UK/AU readers, buy two Crabtree 2-Way 10AX switches and 1.5mm² cabling.

Tools & Materials List

Do not start this job without a non-contact voltage tester and a digital multimeter. Guessing if a circuit is dead is how people end up in the emergency room.

  • Switches: 2x 15A 3-Way Toggle or Rocker Switches (e.g., Leviton 5603-2W)
  • Wire (US): 14/2 NM-B (Line and Load runs), 14/3 NM-B (Traveler run between switches)
  • Connectors: Wago 221-413 (3-port) and 221-415 (5-port) lever nuts, or IDEAL 341 wire nuts
  • Testers: Klein Tools NCVT-3 Non-Contact Voltage Tester, Fluke 117 Digital Multimeter
  • Hand Tools: Klein 11-in-1 screwdriver/nut driver, wire strippers (calibrated for 14 AWG solid), lineman's pliers
  • Tape: Red and black electrical tape (for re-identifying neutral wires used as travelers)

Mains Safety Protocol

DANGER: LETHAL VOLTAGE. Working on mains circuits (120V/230V) can cause fatal electrocution or arc flash. According to OSHA electrical safety standards, you must de-energize the circuit before touching any terminal.
  1. Turn OFF the branch circuit breaker at the main panel.
  2. Apply a lockout/tagout device if you are not the only person in the building.
  3. Test your NCVT on a known live circuit (like a receptacle) to verify the tester works.
  4. Test the target switch wires. If the tester beeps or lights up, STOP. You turned off the wrong breaker.
  5. Verify dead with a multimeter set to AC Voltage (Line to Ground should read 0.0V).

Note: NEC-style guidance is provided here; your local AHJ (Authority Having Jurisdiction) has final authority. If you are unsure, hire a licensed electrician.

Step-by-Step: US 3-Way (Global '2-Way') Wiring

This procedure assumes a standard US NEC installation where power enters at Switch Box 1 (Line), and the light fixture is fed from Switch Box 2 (Load). NEC Article 300.3(B) requires all conductors of the same circuit to be routed in the same cable to prevent inductive heating; this is why we use 14/3 for the travelers, not two separate 14/2 cables.

  1. Prep the Boxes: Strip 3/4 inch of the outer NM-B jacket. Strip 1/2 inch of insulation from the individual 14 AWG copper conductors. Do not nick the copper.
  2. Identify the Line and Load: In Box 1, the 14/2 cable from the panel is your Line (Black=Hot, White=Neutral, Bare=Ground). In Box 2, the 14/2 cable going to the light is your Load.
  3. Wire Switch 1 (Line Box):
    • Connect the Bare/Green ground wires together with a pigtail to the Green Ground screw on Switch 1.
    • Connect the White neutral from the Line cable directly to the White neutral of the 14/3 traveler cable using a Wago 221 connector. (Neutrals bypass the switch).
    • Connect the Black Line (hot) wire to the Black (Common) screw on Switch 1. This is the only wire that lands on the dark screw.
    • Connect the Red and White wires of the 14/3 traveler cable to the two Brass (Traveler) screws. Tip: Wrap black electrical tape around the white wire ends to re-identify them as hot travelers, per NEC 200.7(C).
  4. Wire Switch 2 (Load Box):
    • Connect the Bare/Green grounds together and pigtail to the Green Ground screw on Switch 2.
    • Connect the White neutral from the 14/3 traveler cable to the White neutral of the 14/2 Load cable using a Wago connector.
    • Connect the Red and White (taped) traveler wires from the 14/3 cable to the two Brass (Traveler) screws on Switch 2.
    • Connect the Black Load wire (going up to the light fixture) to the Black (Common) screw on Switch 2.
  5. Secure and Dress: Fold the wires neatly into the back of the boxes (grounds first, then neutrals, then hots). Drive the switch mounting screws to 0.75 in-lbs torque. Attach the faceplate.

Step-by-Step: UK/AU True 2-Way Wiring

For readers in 230V regions using IET BS 7671 or AS/NZS 3000 standards, the physical switch terminals are labeled COM, L1, and L2. You will use 1.5mm² Twin & Earth for the line/load, and 1.5mm² 3-Core + Earth for the strappers (travelers).

  1. Switch 1: Connect the Brown Line (Live) to the COM terminal. Connect the Brown and Black strappers to L1 and L2 (order does not matter). Connect Earth to the earth terminal.
  2. Switch 2: Connect the Brown strappers from Switch 1 to L1 and L2. Connect the Brown Load (Switched Live to the lamp) to the COM terminal. Connect Earth.
  3. Neutrals: Connect the Blue neutrals together in a Wago block at the back of the box; they do not terminate on the switch.

Verify & Test Protocol

Do not just flip the breaker and hope for the best. Perform these bench-style checks before energizing.

  1. Continuity Check (Power OFF): Set your multimeter to Continuity (the diode/beep symbol). Place one probe on the Common screw of Switch 1 and the other on the Common screw of Switch 2. Flip the toggles. You should hear a beep in exactly two of the four possible toggle combinations. If you get a beep in all four or zero, you have a short or an open traveler.
  2. Short Circuit Check: Place probes between the Common screw and the Ground screw on both switches. The meter must read 'OL' (Open Line / Infinite resistance). If it reads near 0 ohms, you have a ground fault. Fix it before energizing.
  3. Live Voltage Test (Power ON): Turn the breaker on. Set the multimeter to AC Voltage. Measure between the Common screw on Switch 1 and Ground. You must read 114V to 126V (US) or 216V to 253V (UK/AU). Measure between the Load wire at Switch 2 and Ground while toggling the switches; voltage should appear and disappear cleanly.

The Most Common Botch & How to Fix It

The Symptom: The light only turns on when Switch A is in the UP position. If Switch A is DOWN, Switch B does nothing, and the light stays dead.

The Cause: You swapped the Common wire with a Traveler wire on one of the switches. This is the single most frequent mistake made by DIYers wiring a 2-way/3-way circuit. Because the traveler screws are brass and the common screw is black (or distinctly marked COM), people misidentify the incoming hot or outgoing load wire and land it on a brass traveler screw instead.

The Fix: Turn off the breaker. Identify the wire that is the true Line (in Box 1) or true Load (in Box 2). That specific wire must land on the dark-colored Common screw (or COM terminal). The two remaining wires in that 3-conductor cable are the travelers and must land on the brass screws (L1/L2). If you are using a smart switch (like a Lutron Caseta), the wiring topology changes entirely—always defer to the manufacturer's specific diagram, as smart switches often require a neutral at both boxes and do not use traditional traveler strappers.

Final Rule of Thumb: Never use a standard single-pole switch in a 2-way/3-way circuit, and never wire two 3-way switches without the 3-core traveler cable. If your existing boxes only have 14/2 (2-core) between them, you cannot wire a standard dual-location circuit without pulling new wire or installing wireless smart relays. For deeper code compliance on switch loops and neutral requirements, refer to the NFPA NEC Article 404.2.