Here are some typical problems with old wiring that are possible hazards and may indicate the wiring should be replaced:Cracked,missing,or damaged wire insulation,exposing the metal part of the wire.Wiring surrounded by building insulation of any type.Exposed splices (not in an electrical box) wrapped with modern plastic electrical tape,.. Is My Old Electrical House Wiring Safe? Is this answer helpful?Thanks!Give more feedbackThanks!How can it be improved?How can the answer be improved?Tell us how Is My Old Electrical House Wiring Safe? - The Spruce The oldest type of wiring system found in homes is called knob-and-tube, named for the insulating knobs and tubes are used to run the wiring along and through the house framing-and-tube wiring was run as individual wires—one black hot wire and one white neutral wire—throughout the home. The insulators keep the wires from touching each other and the wood other combustible materials. How dangerous is old electrical wiring? - mcgarryandmadsen • Can old electrical wiring go bad inside a wall? • What could cause an extremely high electric bill? • How do I trace and identify each circuit breaker in my electric panel to make a circuit directory? • What is the difference between GFCI and AFCI circuit breakers? • What causes flickering or blinking lights in a house?