This is going to sound like a duplicate question but it's actually reversed.
We live in a house built in the 1960's (in the US). We have metal conduit throughout and surprisingly a ground wire that is terminated at each electrical box. Many of the outlets were 2-prong, and I've been replacing them with 3-prong.
I came across one outlet today that confused me. Instead of the standard 4 wires coming in, I only saw 3. And to make things stranger, it was 2 neutrals (white) and one hot (red) attached to a 2-prong screw terminal duplex-X receptacle (all 4 holes are T-shaped). Also it is a switched outlet.
Has anyone ever seen something like this? Is there a way to convert this to a 3-prong receptacle?