- Mis-wired receptacles. Consider using a Suretest rather than a $12 tester for more accurate readings.
- Outlets installed above electric baseboard heaters.
- Many receptacles installed upside down.
- Lack of GFCI or AFCI protection.
- GFCI or AFCI receptacles that don’t respond or respond poorly to testing.
- Missing cover plates.
- Scorched or damaged receptacles or switches.
- Inoperable or weakly operating switches.
- Inoperable or intermittently-operating lights
- Improperly-terminated wires. Just because they don’t carry current when you test doesn’t mean there isn’t a switch somewhere.
- Improper conductor types like Romex used outside.
- Antiquated wiring like cloth-covered or knob & tube.
- Garbage disposal wiring run through kitchen cabinets.
- Improper garbage disposal wiring (dedicated 20-amp circuit, hardwired or factory cord, splices in junction boxes with covers).
- Conductors exposed to potential damage from impact or abrasion.