In Haunted Brighton  Alan Murdie discusses a case of odd optical effects reported by residents of Shirley Street and Clarendon Street in Hove, 2002-3, which some commentators attributed to ghosts and others to UFOs or extraterrestrials.
The phenomena took the form of ‘Xs and bars which flicker along… [the] street’ , or ‘perfect circles of light with a pronounced X at the centre’ . Murdie reservedly remarks that ‘interpretation of the light markings… [was] very much in the eye of the beholder’ (p.44), but concludes: ‘no single explanation has yet conclusively accounted for all the sightings’ (p.45).
I was intrigued by how this case defied the usual categories of paranormal experience, so I spent a morning in the library digging for the original reports. Sure enough, there they were: photographs of odd lights on the walls of houses along the affected streets, although much detail had been lost in the conversion to microfilm.
Concluding that there was nothing for it, except to organise a team and stake out Shirley Street, to see if the lights would show up again, I was making my way across town when a possible explanation for the case loomed up right before me.
What could possibly be causing this? Spectral forces from beyond the grave? Space brothers from Venus? Crossing over the road and making the daring experiment of putting my head in the place where the lights appeared, I saw the following.
The circles and crosses were caused by the reflection of sunlight from a paned window across the street. Ironically, I was on Robert Street, Brighton, and the building whose windows cast the reflection was formerly the offices of the very newspaper that had seen fit to print the reports.
For the lights to appear the sun would need to be at an low angle to and parallel with one side of the street, so that its light could hit that side and be reflected onto the other. This meant that the effect could only occur in the morning or evening and would not be observable during the bulk of the day.
Of course, I could not be sure that this fully explained the rumours of spooks and aliens in Shirley Street. Strictly speaking, I should have made the effort to make the same observation on the actual site. Yet it now seemed to me highly likely that this simple phenomenon was indeed the cause. Wondering why no one else had been bothered simply to put their head in the way of the lights and see their source, I continued on my way, wiser and sadder.
 Alan Murdie, Haunted Brighton (Stroud: Tempus Publishing, 2006), p. 44-45. Further references are included in the text.
 The Argus, January 14th (2003), p. 13.
 The Argus, December 20th (2002), p. 3.