Hey all
Yet to get caught out in that way, though I see how easily it could happen!
My usual problem is the credit-card sized tool I keep in my wallet. Always gets inspected after I forget to remove it, vut it's passed so far. I imagine rings would also pass, but getting through the inspection is the challenge!
I was going into a federal building one time and forgot I had my ring on until just before I got inside. I put my hands in my pants and took it off and put it in my pocket. Then when I put all my stuff in the tray I put it in there under my wallet. But, the guy pulled my tray through and look at my stuff and was confused for a brief second and then realized what it was. He asked why I had that in there, but I just picked up my stuff and went on my way. I wish I could have thought of something clever to say.
I have a suit with rings on the sides that has gone through the airport scanner without being noted - perhaps they thought it was my wife's suit. :-)
As for building security, it's been a while since I encountered that. I'd be in the same situation. Could I pass it off as being for a home project, or just say I assumed it needed to be removed for the scanner? :-D