Yes, many times.
At the risk of being accused of being insane, I will tell you about it. There is a difference between having some paranormal type experiences and being mentally ill. My experiences do not occur very often (up until recently...and then they only occur now when I want them to), they do not involve discarnate voices telling me what to do or giving me a commentary on my life. When this sort of stuff is NOT happening I'm a perfectly normal person (well cough cough you know... lol)
Now thats out the way:
There are different ways for spirits to appear to us. I've seen spirits who look as solid as you or me. The only way you know that they are spirits is that they appear somewhere surprising (like in my room at night) and they disappear right in front of your eyes.
Some spirits appear as "energy" - lights or movements which you notice fleeting by or from the corner of your eye.
Most often I experience spirits in my minds eye. So I "see" them but not with my physical eyes. Of course it could be suggested that these are my imagination. The surrounding experience and information is a guage as to whether I made it up or not! lol. If I "see" a spirit and I'm with a person I don't know....and I describe that spirit in detail (height, hair colour, description, including their personality and other things I couldn't have previously known) then I accept that I didn't imagine it. Plus, the feeling is very different when I sit and deliberately imagine something compared to this experience of a spirit actually being there.
You cannot touch them, in my experience, unless you have had the visit in a dream. In which case its as though they're really there. I've had touches from spirits though, like little strokes of my forehead, or a breeze in my face.
I'm currently training my mediumistic abilities. For all these years I knew I could see spirits but I shied away from actually developing it.