Would Putting In a GFCI Correct an Open Ground?
A user asked the app whether installing a GFCI receptacle corrects an open ground. The precise answer is no, a GFCI does not create or repair a ground, but yes, it is the Code approved fix for receptacles on circuits that have no ground available. Those are two different statements and mixing them up causes failed inspections and confused home inspection reports.
What 406.4(D) permits
NEC 2023 Section 406.4(D)(2) covers replacement receptacles where no equipment grounding conductor exists, which is the situation in most pre 1962 two wire homes. You have three options: install another two prong receptacle, install a GFCI receptacle marked No Equipment Ground, or install a grounding type receptacle downstream of a GFCI marked both GFCI Protected and No Equipment Ground. The stickers come in the GFCI box and they are not optional. An inspector or a tester that flags open ground on a labeled GFCI protected receptacle is reporting exactly the condition the Code allows.
The reason this is acceptable is how a GFCI works. It compares current leaving on the hot with current returning on the neutral. A difference of about 5 milliamps means current is finding another path, possibly through a person, and the device opens in a fraction of a second. That protection does not depend on an equipment grounding conductor at all, which is why the Code accepts it as a life safety substitute on old wiring.
What it will not do
A GFCI cannot give surge protectors a path to dump transients, so plug in surge strips do little on an ungrounded circuit. It will not stop a three prong tester from reading open ground, because the tester is telling the truth. Sensitive equipment that wants a reference ground still lacks one. And if the circuit originally had a ground that is now broken at a splice or a device, the right repair is to find and fix the break, not to paper over it with a GFCI: an open equipment grounding conductor on a grounded system is a defect under 250.4. When a real ground is wanted, 250.130(C) allows running a separate equipment grounding conductor from the receptacle back to the panel or to the grounding electrode system, which is often easier than rewiring the whole run.