simple on-off switch; one-way switch (UK); two-way switch (US)
Electrical switch with only two terminals, used for basic on/off control from a single location. Compare with 3路スイッチ (three-way) and 4路スイッチ (four-way) for multi-location switching.
See also: 三路スイッチ (さんろスイッチ) · ４路スイッチ (よんろスイッチ)
This light is operated by a simple on-off switch.
A one-way switch is the type that can turn the light on or off from only one location.
片切 (かたぎり) literally means 'single cut', referring to the single break in the circuit, combined with スイッチ (switch).