If you find any chain hung fixtures during your inspections, without a 3rd equipment grounding conductor (usually a bare wire) run with the fixture wires into the box, that is a DEFECT.
You should also check to see that the grounded conductor is connected to the screw shell.
I touch all overhead lighting with my tic-tracer and write up all the ungrounded fixtures.
Great, check the screw shell for reversed polarity too.
And how do you do that without removing the shell? I’m not about to remove covers to check splices.
David:
The screw shell is where we screw in the lamp, and when the lamp is exposed the tic tracer should not buzz and glow when you touch the screw shell, that’s what I meant.
So in order to access this electrical conection, the bulb must be removed.
I don’t do bulbs, thank you.
I believe that you can touch a tic tracer to the screw shell on some lampholders.
I guess another excuse would be “we don’t do ladders either and that fixture is way up high above the stairs and would be difficult to reach.” 
Joe,
Now we’re back to were we started this conversation…
Now how does this tell me that the wiring has reversed polarity?
David: The branch circuit supplying the ceiling outlet may be properly wired, but if the fixture wires were reversed then the screw shell would be hot, that’s what I mean.
I guess I will have to do a video on this, but cannot for a while until I can get a 10 foot ladder into my place, but we could try a simple table lamp with two straight blades on the cord cap, I have one and will unplug it and demonstrate what I mean.
Joe,
When I’m touching an appliance and my tic tracer light goes off, I write it up as an un-grounded appliance and I recommend a licensed Electrician to evaluate and correct.
I don’t see where I can differenciate between an ungrounded outlet and a reversed polarity with a tic tracer.
Sorry for confusing you, I can only make it clearer to you in person in the field someday.