Today is Halloween, when ghosts are thought to roam the streets looking for bodies to possess. Many people insist that ghosts don't exist, but those who have actually seen one are convinced that they are for real. 'More and more people are starting to believe in the existence of ghosts,' says Frances Fong, who hosts The Unbelievable on Cable TV. The show offers viewers a chance to share their unexplained ghostly encounters, and investigates stories and sightings. 'It's because television, radio, movie actors and artists, and the general media are always telling 'real ghost stories'. People are more exposed to such stories now, so they start to believe in them,' she says. 'One of the most memorable stories we heard on the show was about a little boy who was being harassed by a ghost. A family friend had called in asking for our help. We were still talking about the case when the five lights that light up the set all went off at the same time. We all felt a presence then. 'People encounter ghosts in different ways. Some can see them, while others can only feel them or hear them. Some can even see holy, spiritual beings. Only people that are pure of heart, such as children, can see them.' Claudia Massey was 11 years old when she saw a ghost at Marymount Primary School. Now aged 15, she tells her story: 'Every day we had a morning line-up at school. Someone always played the piano. That day I was playing it. Afterwards, I left to go back to the classroom, and looked back to check if I had forgotten something. 'There was a statue of Mary on the stage, and I saw this man, wearing Victorian clothes, begging for forgiveness. I glanced away, and when I took a second look, he was gone. I was terrified. I felt he had done something bad. It was the old-fashioned clothes and the way he disappeared that scared me.' Miranda Chiang Hei-yin, 18, at Wong Tai Shan Memorial College recalls her experience: 'Once, my sister and I went home at night, and caught the last MTR back to Lok Fu. Only a few people were in our carriage. One of them, a woman, sat opposite us. She wore a long purple skirt, and looked at me once. 'I thought she was a little bit weird, dressed in purple like that. But when we got off the train, and I told my sister that the woman looked terrible with that purple dress, she said she hadn't seen anyone in our carriage.' The idea that we can die and return as ghosts is what disturbs people, says Fong. 'People are scared of ghosts because they can't see them,' she says. 'They are scared of the unknown. People think ghosts are powerful and can harm the living, but sometimes, these ghosts contact the living because they want people to help them. 'The kind of people that are most likely to see ghosts are people under the influence of alcohol or drugs, those who have a long-term illness or are bad tempered or have bad luck,' Fong says. Doctor Alvin Chan Yee-shing, a child neurologist who has treated patients with psychological problems, says ghosts are not real. 'All sightings can be analysed scientifically. It could be a psychotic episode, a symptom of neurosis, anxiety, or even hallucinations induced by epilepsy. People who see ghosts should get counselling to share their worries and frustrations.'