Yes, I have seen them on many occasions. Anyone can, it isn't a 'paranormal' skill, it's a normal one. Kids usually see them more easily than adults, but only up to the age of 5 or so. After that, they learn that they aren't supposed to see them and have been told 'there's no such thing' enough times that they lose the ability.
If you think you have a ghost and want to know for sure, practice asking whatever question you might have and then focusing on the area toward the front of your forehead. It helps if 1) you expect an answer, 2) you are very relaxed, and 3) you take the first image or impression you get. It might not make sense at first, but keep practicing and you will soon receive these images spontaneously. That is how you can 'see' ghosts. That's where I see them anyway.
Also, this is a good way to find car keys and what not.
As far is ghosts manifesting right in front of you, that happens but only very rarely. Most people overreact to the possibility that they have a ghost. They can't really do anything to you, and mostly they don't want to.