knob-and-tube wiring; insulator wiring
Refers to an older electrical wiring method where wires are run along surfaces using ceramic insulators (knobs and tubes). Primarily a technical term in electrical engineering and construction.
In old houses, knob-and-tube wiring sometimes still remains.
Knob-and-tube wiring is considered less safe compared to modern wiring methods.
Commonly used spelling with がいし in kana and 引き工事 in kanji.
Rare kanji spelling using 碍子 for insulator; 碍 is not a jōyō kanji.
Compound of がいし (insulator) + 引き (pulling, wiring) + 工事 (construction work). The term describes the practice of pulling wires through or along insulators.