An odd bloke makes a local news story – he says he can see ghosts. It is presented as something a bit daft and funny.
But the crew of a ghost-hunting video show notice and decide to leverage him, one way of another.
When they recreate one of his sightings, he swears he can see ghosts, yet nobody with him, or the video camera, sees it. Yet he seems very genuine…
They painstakingly walk through the sighting in careful detail and realise that every time he sees a ghost it is around 7 metres away. They place him 7 metres from a wall, and get him to look at the wall… it soon becomes apparent that he only sees ghosts when they are between 7 metres and 7.3 metres away.
Years late they have developed a video camera capable of focussing to fine degrees of distance, and film him enacting the encounter. By changing the focus by 1mm at a time, they find the sweet spot – 7.132M – and the camera picks up ghosts.
Once her starts indicating he can see them, the ghosts start responding. Something needs to be done, and the drama begins.
This is why ghosts are mostly seen in old mansions. You need to be focusing on something 7M away, mostly a wall. And because you are unlikely to be standing still at the precise distance, as you move you get a fleeting glance of the ghosts.