According to dpb :

There are some plug-in-the-wall circuit testers but I have to honestly
say I've never used one and don't know just how reliable they are for
testing for the ground connection.

Three-light plug or neon testers are sufficient to tell you
that a ground _exists_ (in the former, the two green lights but not
the red one light up), but not how "good" the ground it is. If
they light up appropriately, the ground is almost guaranteed to be
good enough to trip a GFCI. But it's nowhere near a certainty that
a hot-ground short would trip the breaker.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.