Listen to the story here.

I am quite sensitive to this kind of beings. Some years ago, I and my friends could sense it, by snapping around with my camera. My camera has helped me a lot in capturing these things using the techniques that I learnt from SPI website.

One strange encounter that I can share, is what my friend who works in police force told me about. One night, before they went out for patrolling, they attended a briefing session. They were told that there was 'something' in the neighbourhood. One day their team leader had received a 999 emergency phone call from a fixed line at their command center. The call came in repeatedly for several times with a woman's voice saying "Help me! Help me!" then just hung up. When they started chasing the call, the call was traced to an abandoned factory. The factory was no longer in use. The search team climbed into the factory to investigate. They found no furniture, nobody, no telephone in the factory all.

This is only a very minor case that I can share with you. There are many other more drastic cases. However, they are classified.