I was replacing some old outlets in an old rental property that I have. After replacing and ensuring I added grounds to the metal box where needed, I began testing the outlets. My GFCIs triggered properly and most outlets gave me the "ok". HOWEVER, I have one circuit of outlets/light that give me the following on the tester:
middle light on strong, right light low and left (RED) light low.
When I hit the button that would trip a GFCI, I get a strong RED and a strong MIDDLE and no right. This indicates a hot/neutral situation. Am I correct in assuming this? If so, it means that somewhere in the circuit I have a black and white tied together? I guess I just work backwards towards the BOX to troubleshoot this?