TL;DR
A three-way switch is one of a pair of switches that control the same light from two locations, such as both ends of a hallway or stairwell, using a common terminal and two traveler wires between them. The toggle carries no ON and OFF markings because either position can be live depending on the partner switch.
What it means
A three-way switch is one of a pair of switches that control the same light from two locations, such as both ends of a hallway or stairwell, using a common terminal and two traveler wires between them. The toggle carries no ON and OFF markings because either position can be live depending on the partner switch. The dark-colored common screw is the key landmark in wiring one, and miswired travelers are the usual reason a light only works when both switches sit in particular positions.
Where it sits in the glossary
Three-way switch is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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