Oh but this is actually a bit altered line from a poem by William Hughes Mearns:

Yesterday, upon the stair,
I met a man who wasn’t there.
He wasn’t there again today,
I wish, I wish he’d go away…

When I came home last night at three,
The man was waiting there for me
But when I looked around the hall,
I couldn’t see him there at all!
Go away, go away, don’t you come back any more!
Go away, go away, and please don’t slam the door…

Last night I saw upon the stair,
A little man who wasn’t there,
He wasn’t there again today
Oh, how I wish he’d go away…