Knob and tube(redirected from Knob and tube wiring)
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Knob and tube
In electrical work, a means of concealing wiring and one of the earliest methods to wire a house. Insulated wires are supported with porcelain knobs and pass through porcelain tubes in wood members of a floor or wall. Although it still meets the National Electric Code, it is not approved by many local organizations, and it is used only for temporary installations such as construction shacks.