I used to live in a Victorian terraced house which had a small back yard, fully enclosed by a 6 foot fence, with a full length wooden gate with 2 large bolts on it. Anyway, I was washing up one day, and the kitchen window was above the sink and overlooked the garden. I told my daughter, who was 3 at the time, to go and play outside whilst I washed up, but she kept coming back inside.
Eventually, I asked why she wouldn't go and play outside, and she said it was because she didn't like the man who was out there. From the window, I could see there was nobody in the garden, so I took her by the hand, walked outside, and asked her where the man was. She pointed straight ahead, at nothing I could see, and said, 'he's there!'
I took her to play school, and went off to work, and she told the teachers at play school, and my parents who picked her up and had her until I finished work, all about the man in the garden, with no variations to her story.
We used to get quite a lot of strange things happen in that house...