No one has actually seen it, but a fairy interpreter asked a fairy and they described it as just a cloud of smoke and once in a while you trip over something in the floor.  The fairies purposely leave their trash in the floor because they think it is funny when people trip over them.
Inside the fairies church, Inside Church
bluebird
fairy interpreter
I live in the fantasy world.  I love to be a means of communication.  I love to help.
Isn't it marvelous!  beautiful!  You voice is so majestic! I only wish there wasn't trash on the floor... Yes it is an eye sore, but when unsuspecting people walk through and trip over them, it so hilarious!  haha! if only they had wings like us! They are funny creatures! whoops! oh no! I just tripped over some garbage  Maybe if I would clear out all this smoke, you could have been that trash! so embarassing! My trash? Or the fact that you tripped over it? That I tripped, silly!