Outlet voltage is read against the 120 V nominal. About 120 V is nominal; about 0 V means no measurable supply at that point; roughly half nominal is abnormal but not diagnostic because a high-impedance meter can show phantom voltage and a persistent abnormal reading can also occur with an open neutral or another wiring fault; ~240 V at a 120 V outlet is a serious miswire.
source-governedDiagnostic estimate. Not a quote, not a substitute for a licensed electrician.source pack dated 2026-09-12 · authority hashes pending
Where to stop. Measuring at an accessible outlet or on a disconnected wire/fuse is homeowner-safe with a properly rated meter. Anything that requires probing energized wiring inside boxes or the panel is a licensed electrician's job. Note that digital meters can read phantom (ghost) voltage on a de-energized conductor — confirm a live/dead decision with a low-impedance meter or a solenoid tester, never a single high-impedance reading. Persistent abnormal line-to-neutral voltage can indicate an open neutral or other wiring fault and should be handed to a licensed electrician. This is general information, not a quote and not a substitute for a licensed electrician.
Electrical Fault Check provides general diagnostic information only. It is not professional advice, not a quote, and not a substitute for a licensed electrician. Do not work on live wiring. If you see smoke, sparks, burning smell, heat, shock, water exposure, or repeated tripping, stop using the circuit and contact a licensed electrician or emergency services as appropriate.