Published
Knob-and-tube wiring isn't inherently dangerous if undisturbed and properly maintained. But it becomes a hazard when insulation is blown over it (fire risk), when it's been modified by non-electricians, or when it's powering modern loads it was never designed for. Many insurance companies won't cover homes with active knob-and-tube. A full rewire is typically $8,000-15,000 depending on home size.