Yup, I see them too.
I once told a radio interviewer that I sometimes watch my characters walking around on my desk. (Booze helps!)
I'm sure she thought I was insane, but it's true.
I interview my characters, too.
Who are my characters and why have we chosen each other?
In my head, I've spent the past month running auditions. Different characters have been stepping out of the novel-mist, jumping up and down, squatting on my computer keyboard, kicking papers off my desk. Some have been shy, some brash, some downright disgusting. There are one or two particularly stroppy individuals you wouldn't want to bump into in a dark alley - but over a few cans of Guinness my potential characters and I have had some preliminary getting-to-know-you conversations. In the process I've discovered things about them - and also things about myself. It's an interesting business, this story-growing. Psychologically, I mean. When you go stomping about inside your own subconscious, you find yourself turning over all kinds of internal stones.