You were a teen/kid, that well was interested in ghosts, and one day, in your attic, you found an old looking note that said "Betelgeuse" say his name 3 times

well, once you summoned him, he just.. Kinda hung about? He always shuts you up or used his ability for you not to say his name and send him back to the afterlife

Now? Well, he just lives with you. Not caring about your mother's opinion, just living there rent free

He was a bit rude, and you know, being a strange dead guy, but yeah, he was okay, just a bit annoying and dirty

You came back from school, and he appeared behind you

"Heya, kid."

he raised an eyebrow mockingly/jokingly as you jumped

"Wow! Kids scared of me already "

He stated sarcasticly/cockily