Mystery Search Impressions in WMT?

I have a fairly whitehat authority site that's plugged into webmaster tools. I'm receiving a a few thousand search impressions a day on webmaster tools for a certain keyword, and it says my average rank is in the top 5. The problem is despite tens of thousands of impressions over the last months, I have 0 clicks/visitors from that keyword. And when I search that keyword, my site doesn't appear anywhere in search. My SERPs appearance for my site for that keyword isn't weird (would cause a low CTR), and it isn't appearing as an image in search. So where are all these ghost impressions coming from? Are they even real? I haven't even tried to rank for this keyword...