Is there any old wise tale or folklore, meaning when a hawk flies into a building and sets awhilethen leaves. Thank you

Hmm. Can't think of one specifically, but it does sound a little familiar. Something about a hawk or falcon flying into a nursery and landing on the end of the cradle. I swear I read that somewhere. Mary Stewart's The Crystal Cave? No. Although merlins (the birds) play a role in that story, I don't think it was from there. Seems like it was a folk tale or something.

Why? Did this happen to you? It's a little unusual for a hawk to do that. If you choose to see it as an omen, I would say it's a message from Spirit. Be open to finding out what the message is.