It depends on how you define 'ghosts'.
I'll tell you a little story. In March this year someone I loved deeply died. It was the woman which I would marry this month.
I've bever really believed the fact that there are people who could speak to those we have lost. The fact that my girlfriend died did something to me that at first was something that came to me as the shock. But being advised by a remarkable friend made me realise that it wasn't my mind playing tricks. And after reading about it, going to her grave and being completely open for what I felt, I saw what happened. She wanted to talk to me, to ask me a final question. And this was the only way to ask that question.
Is it a ghost? Yes. But not the spooky one. And not everyone can see or talk to them. If you want to block them, they will ignore you. And believe me when I say: it's not a blessing or gift. It's a world full of pain.
Because of the nature of the subject, it's very hard to find people who are willing to talk about this. Business will use it to make money, and science ignores it, because it's difficult to test it.
Who am I? 26 years old, C# programmer for a multi-million company. A year ago I laughed at your question. Now I'm answering it, because you asked for it.