ANSWER: Amateur electrical work
Check out this Frankenstein electrical system. This is an older house with obsolete Knob & Tube (K&T) wiring, which was commonly installed from the 1880s to the 1930s. K&T wiring consists of single insulated copper conductors wrapped in flexible cloth sheathing. The wires pass through floor joists and wall studs via protective porcelain 'tubes' and are supported by porcelain 'knob' insulators, hence the name Knob & Tube. K&T wiring was never designed to handle today’s larger electrical loads. Additionally, it was not designed to be spliced with modern wiring, as it only has two wires; modern wiring has a third ground wire. K&T wiring is also easier to damage as it is wrapped in cloth that can become brittle over time, which results in electrical hot spots, arcing, and fires. Most home insurance companies will not write new policies on homes with K&T wiring. This home’s electrical system should be upgraded to a modern electrical system by a licensed electrician. Depending on the amount of K&T wiring present and in use, additional circuits may be required. The breaker panel should also be upgraded to accommodate the additional circuits.