I'm not a believer, purely because I have not seen proof. Show me some proof and I will change my mind.
That's o.k.. No one is saying you have to believe, and it may be that physical proof would never be a possibility anyway.
I've never to my knowledge actually seen - as in made physically visible to my eyes - an apparition. I have however been made aware through a variety of experiences that there's more out there than is easily explainable. None of my experiences were actively sought by me - they just happened!
The scariest was years ago (posted this before) when I'd been lent a cottage for a few weeks holiday. On arriving I went round to check which of the three bedrooms I would sleep in and as I opened the door of one at the back I was aware that something got up from where it was sitting on the edge of the bed and moved straight towards me. It was so sudden and unexpected I closed the door, feeling sick to my stomach. Then after a strict word with myself I opened the door again and it was still there totally filling the gap; had I tried to walk through I knew it would feel like trying to walk through thick jelly. Anyway I closed the door again and chose a different bedroom. I somehow had no worries because I think I knew whatever it was couldn't come out of its 'own' room. I enjoyed my holiday, but a few days further in when I decided to have a look through the window of that room and approached from the back garden, I could get no closer than a few yards because there was suddenly some kind of protective but invisible barrier... I mentioned this on my return to the colleague who'd lent me the cottage and she said they hadn't told me about this presence beforehand as not everyone experienced it! She also said that her husband who was the most sceptical of men refused to go into that room because he too was aware.
On other occasions it's been as though a little window has opened very briefly in my mind and I know about something that's going to happen, then the window closes again and I forget what I've seen, until later - one time it was a year later, when somebody I'd never heard of before (Benazir Bhutto), was assassinated. It was then I remembered seeing her briefly on a news item on tv and having the prescience of her death for what was perhaps only a split second...
Other things too, but different, and I've met others who've had unexplainable experiences - not all bad but weird at the time. One woman who was away and worried about leaving her husband who was in poor health, 'saw' him twice and realised he was all right; when she got home his first words were something like 'o thank God you're o.k. I thought something happened to you because I saw you out of the corner of my eye when I was watching tv and again another evening when I was getting ready for bed.' Those were the circumstances in which she had seen him, too.
There are more things in heaven and earth, Horatio... and all that (thanks Shakespeare!) 