A receptacle that reads 'open ground' on a tester in a house with modern wiring most likely indicates:

An open ground means the receptacle's grounding terminal has no continuous path back to the panel's grounding system. In a house wired with modern cable that includes an equipment grounding conductor, the path exists by design, so a reading of open ground indicates the connection was broken somewhere: a grounding pigtail not made up in the box, a wire that backed out of a terminal, a device replaced without reconnecting the ground, or a break upstream affecting several outlets. The consequence is that fault current has no low-impedance route home, so a fault to the metal case of an appliance may energise it instead of tripping the breaker. The inspector reports the condition and recommends evaluation; identifying which connection failed requires opening boxes, which is beyond a visual inspection.

In a house wired with a grounding conductor throughout, an open ground reading means that conductor has been disconnected or interrupted somewhere between the receptacle and the panel. The inspector reports the finding and recommends an electrician trace and correct it.

Equipment grounding provides a low-impedance path for fault current so that overcurrent devices operate. Three-light testers indicate open ground, open neutral, reversed polarity and similar conditions, though they cannot identify the location of the fault or detect a bootleg ground.

Open Ground Means Broken Path. The wire exists in a modern house — something interrupted it. Report the break, let the electrician find where.

Note how many receptacles read open ground. One suggests a local connection; several on a circuit point upstream, and that distinction is useful in the report.

• •Confusing a grounding fault with an overloaded circuit
• •Naming the receptacle as the failed component without evidence
• •Dismissing the reading as a tester limitation