I was visited in my sleep last night
by someone quite unwelcome...
In fact, I had had that mat removed.
Still, you were there on the inside
of my locked keyless door.
What fool had granted your passage
across my threshhold.
Fully awake now,
I realize that fool had to be me,
for I dwell alone.

cathy clough

http://www.poemhunter.com/poem/strangers-in-the-night/