We have found many strange things in the electrical system of the house
we bought recently:
1. Several outlets in the kitchen were ungrounded. In one of the
"upstream" boxes I found two bare copper wires that were not connected
to each other; connecting them restored the ground to the other outlets.
2. Found one outlet with Hot and Neutral reversed. Easy fix.
3. One 20A breaker in the box seemed to do nothing although it had wire
(12/2) connected to it. Eventually found that it was feeding a single
outlet (a regular 15A one) in the den (possibly intended for a heater,
as the room has no heating vents), but that it runs via a junction box
(to which is also connected the transformer for the doorbell), from
which point on the wiring is only 14/2. Haven't yet decided whether to
replace the breaker or the wire.
4. The wiring to the A/C unit runs from a pair of tied breakers, but the
wiring is 12/2 (+G), with white used for one of the Hot connections.
Haven't yet decided whether to do do anything about it. Would putting
red tape or nail-polish on the white at both ends be an improvement?
5. A pair of tied breakers is labeled "Kitchen," with red and black
wires, but only one of them seems to be used: I cannot find 220/240v
between any two Hots in the kitchen.
6. A red and white are taped together in the box, but I haven't yet
traced them to see what they are all about.