Someone's been trying to log into someone else's account using my username, too.
"sprit" instead of "Spirit"
How does one "log into someone else's account using your username"?

If it is "sprit532" instead of "Spirit532", it is no longer your username. I could happily create an account under that name; don't see why that would be illicit.
I don't see an existing "sprit532" account though. Why do you think someone has tried to use that name?