The breaker unit is separate from an outlet unit serving as an outlet of a plug-in connector for wiring and is to be attached along with the outlet unit to an installation surface to constitute a wiring device. The breaker unit includes a breaking function unit and a housing to accommodate the breaking function unit. The breaking function unit is to be connected between a power supply and the outlet unit and is configured to detect an abnormal current and to break an electrical path between the power supply and the outlet unit in response to detection of the abnormal current. The housing is configured to be held by a fixing member which is to be attached to the installation surface and is to hold the outlet unit.
