I have a story different from the topic. We have a great uncle who made a name for himself and appears in some history books, One. day, a local TV station announced a program where they were taking a relative of his, for trip down memory lane to places around the world where he had lived etc.
We were very curious but we did not recognise this relative although he had the same very common surname. My brother tracked the person down. The funny thing was the more my brother explained our relationship etc, the more he seemed to be the one who was not a relative.
Any way the outcome was that the person had done his family research, but believed his family story that they were related. A lot of disappointment but contact remained cordial. The TV station dropped the idea for the program via their own research. A pity, I think my brother would have liked the trip.