I've never really been into ghosts or spirits, and I've only had a couple of those kind of experiences.

I was an adult and I was in the Edinburgh Fringe Festival. I was performing in this cave - they used to bury the plague victims in these caves underneath the streets of Edinburgh, when I got this weird cold sensation up my spine, it gave me this really weird feeling, and then I looked up and there was this white, sudden white shape, that just zapped from me and went straight to the light that was at the back of the room, and I just stopped cold and said to the audience, "Did you guys see that?" No one saw it.

I guess, on my list, going back to some old American stuff and British stuff that I used to love in the '80s, would be a British show called Dad's Army, which recently just turned into a movie.

I do want to come across something, I do want to feel something and see something.

One time we stayed at a B&B, and there were a couple of hippies who had this nice little area and they let us sleep in their beds that they had in the back.Then the woman suggested we go out and lie on some cushions and look up at the stars and look for UFOs and she said, "You know, I do this all the time," and I was like, "Okay..." So there we are, lying there next to this amazing loch, and we're looking up in the stars and I don't really know what I was expecting, but to see some sort of metallic object.

When I did The X-Files, there was certainly less of that because the script was as it was and it was such a wonderful script and it was quite complex and there wasn't a hell of a lot of improvising I could do to bring to the table, but I guess what I did bring was a sense of self and that the reason I was cast was because I did come across as someone who possibly was only human for a short time.

When I was a kid I thought I saw a ghost in the forest when I was on a bush walk, like a walk through the forest. I saw something weird pass from one side of the track to the other, and it was sort of a white, blurry... it's hard to describe, really, something that was almost see-through but it just moved in front of me. It was definitely something you could tell was there, and it really freaked me out. I think I was probably 10, and I ran all the way home.