You may have been spelling your name differently, or if you are a woman, you may not have changed your name when you got married.
My husband got a similar letter because when he was in grade school and attending private school, his mother changed the spelling of his name to a more affected spelling. When he went in the service, all his papers reverted to the original spelling. Just contact the SS office or go in and don’t leave until they figure it out. I think that my husband was notified by the company that he works for, and then contacted by SS. Sure enough the SS letter was addressed to the odd spelling of his name.
My first and last name is the same as my fathers and we both thought that meant I was a jr. and every id I had I had a jr. at the end. Enlisted and was told if it’s not on the birth certificate, I’m no junior.
Paid taxes and s.s. for 40+ years with a jr. at the end of my name. When it came time to file for ss it took about 3 minutes to correct.
As for the poster, look closely at his name. I don’t know where the bell star is but I don’t believe it’s any where near this world.
Alien and not the kind that swims across the Rio Grande.