Is this just the mysterious stranger from fallout?

Perhaps, but if you exorcise Tyler the spirit may just go back to the crow and either find someone else or come back later. Which makes me wonder if killing the crow would just make the spirit latch onto something or someone else. I think another idea would be to try to learn more about the entity itself- what it is, where it came from and how to keep it there.

Kill the crow, if you can. Crows in some folklore carry the souls of the dead. This entity is using the crow to pass on into Tyler. Maybe try closing the curtains, or even painting over his window in some way?