Ghost in strong sunlight

So I was looking across a familiar suburban street recently one late sunny afternoon. I noticed a figure in front of a house opposite. The person was walking by the front door when suddenly they vanished! So, a ghost then!

There was nothing obscuring the view and nowhere for the figure to go – it just disappeared. I was puzzled for a while until I worked out what was really going on. The figure was a reflection of a person on the near side of the street who I could not see directly because of a tall fence in the way. I couldn’t easily see there was a large window in the front door because the strong sunlight was throwing that whole area into deep shadow.

So why couldn’t I see the background behind the figure that would have revealed it as an obvious reflection? Well the background was the tall fence that just looked dark and featureless. Meanwhile the human figure was strongly illuminated by the sun.

This ghost effect could only work at certain times of day, in sunny weather and at certain times of year due to the angles involved. It also had to be viewed from just the right position. So it was an example of a ghostly sighting caused by a coincidence (see here).

My experiences with reflections (see here for instance) are leading me to think that they may be a significant source of ghost sightings.