[joseph62]

I am in the process of selling my house. The home inspection identified 2 outlets in one room as having an open ground. When I test the outlets with a receptacle tester it indicates an open ground. When I use a voltage tester, one end in the hot slot the other in the ground, it lights up. Why is this happening?

Thanks

[21boat]

There is still a circuit there being a hot and a neutral. A ground wire is not present or not hooked up.
The basic
Black wire hot
White wire neutral
Green/ or bare wire ground

The bare or green wire is "Open" not hooked up
So either these not a ground wire there or the outlet wasn't hooked up with a ground wire or its not hooked in the panel box or another outlet in that series was forgotten to be grounded therefore the rest in that run is not grounded.

Expose outlets and check for ground wires

[Perito]

The home inspection identified 2 outlets in one room as having an open ground.
When I test the outlets with a receptacle tester it indicates an open ground.
When I use a voltage tester, one end in the hot slot the other in the ground, it lights up. Why is this happening?

I suspect your voltage tester.
It may be an inductive type that lights up even though there's no ground, though that doesn't seem likely if you have two leads. There may be a high resistance through the ground. If you have a good ohmmeter, you could check the continuity between the neutral and the ground pins. It should be very low.

Alternately, just open up the box and take a look.