Do ghost really exist?is there any indications of them?

I have had personal experiences and had my name called out three different times in two different places and indeed you can come to question your sanity. The third time which happened in New Orleans of all places, caught my by complete surprise as I was on vacation and i simply did not expect to have such an encounter. I was visiting for Mardi Gras and just out of nowhere I heard my name called out and as you described , it was in such close proximity to my ears I anticipated that I was hearing it inside my mind . The voice called me out and just said "Tim, Im right behind you", It got my complete attention.then said it again"Im right behind you". The individual with I had been traveling with was not with me at that particular moment and I knew where he was so It was not any kind of prank. I was completely creeped out and was not sure how to feel about this experience. I have asked a few individuals who are familiar with these types of encounters and they said it could of a spirit guide and that I may of heard them "psychically" . In my mind. When I did hear this particular voice , it did sound like it was in stereo, like I was hearing it in both ears at the same time. Either way it is a mystery but I know I had this experience and that I have had similar experiences in known haunted locations it just reinforced to me that this world holds many things that we cannot easily explain in reasonable terms.Take care.