The haunted book

Around 1990 I worked at an antiquarian bookshop. I didn't get much money out of it, but I bought a lot of books. Some books contained ghost stories, some were horror books, some were books about hauntings, but nothing could have prepared me for this book. It wasn't scary in itself, it wasn't about hauntings, ghosts or anything like that, but when you started to read it you felt that someone was reading over your shoulder. Not when you put this book away and tried another one, it was just this book. I don't remember what it was about, just that it wasn't scary in itself. And I sincerely hope I got rid of it, but I don't remember that either. All I know is that I maybe have a book you'll have comapny reading and I don't know which one!