Yes, there are "aliens". I was one. I have proof:
Eph 2:12 That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world:
But seriously, folks:
Of the millions of stars in the universe, being orbited by an unknown number of planets, I believe the chances of "alien" life is very real. What form that life takes is anyones guess, but yes, I do believe in the possibilty that life exists elsewhere. Have they visited earth? No. I think most of the "sightings" are either active imaginations, optical allusions, explainable objects (planes, weather balloons", etc.). Spirits? I think not.
As a side note: Remember on Star Trek when they would travel to distant worlds and refer to the beings they encountered as "aliens"? I wonder why it never occurred to Captain Kirk and the crew of the USS Enterprise that is was they, themselves, who were the "aliens".