It turned out, the Black wooden box was a battery operated slide projector, he had placed it up in the bell tower and angled it to shine into the ruins of the church. The sheer cunning hadn't finished there, he had rigged the projector to work from a remote control. The remote control allowed him to change the slide, fade the image in and out and turn the whole lot on and off from a distance of more than 100 feet.
He had briefly flashed across the wall a hooded monk like figure, this is what had scared the teenagers.After this we were never to have another serious attempt at a ghost hunt on this site, however we did go back on many occasions to scare brave teenagers.