odd electrical tester configuration

[Barry Sigler]

I occasionally get all three light indicators lit on my electrical outlet tester. There is no diagram for this scenario on the tester, itself. Near as I can figure out, it has something to do with hots, neutrals, and grounds that are not attached to the correct connections on outlets. Knob and tube figures in this, as well. Any insight?

[John Kogel]

If you click on those blue lines of text below your post, lines 1 and 3, you will see tons of comments all about 3 lights. Thanks, Brian, for this new feature.

It could be an open neutral (very bad) with polarity reversed or it could be something else.
Always check you tester and then call for repairs.