Ghosty's & imaginary friends

[Tillyboo]

Anyone got any experience of their little ones having an imaginary friend or talk about 'people or children' in their bedrooms that you can't see.
What age did this start & what experiences please ?
My 2.7yr old dd has been mentioning 'a little boy' in her bedroom. When I ask her what he looks like she say's 'Like Charlie'. Charlie is her cousin whom she doesn't see that often as he lives 200 miles away and is 6 months younger than she.
Are her thoughts and memories getting mixed up or is she actually seeing something ....
Spooky

ds2 (now 11) had 2 little men who lived in his little fingers when he was about 4. They came out at night. They were called 'Mr Bimble' and 'Bernard'!!!!!!!!!!!!
He seems a normal, well adjusted child and thinks it's hysterically funny if we refer to his previous 'friends'.

ds1 has ghosters in his room. He also sees them coming down the stairs, and sometimes in the kitchen while we are eating. They used to scare him, but now they dont. Mind you, I've seen something in our hall too, not that I'd ever tell him.

On the other hand, he also says there's a boy living in the light fitting in the front room