I am working in a company situated at a 4th floor of an old building. There are stories about the building that it's haunted by a white lady and a kid. I myself had not encountered anything so haunted until last July 24, 2008.
It was already 6:00 in the afternoon when my friend and I decided to wash the cups used by other officemates. Inside the comfort room, I was so intrigued by her digital wrist watch. I kept pressing some buttons when suddenly, a voice called me by the first syllable of my name. The voice is recognizable as one of my close friend's voice. When I responded to her turning my head, I saw no one.
Eventually, my friend and I freaked out. We just stood there, wide-eyed right in front of the mirror. Unfortunately, there were still other cups unwashed. So we then decided to close the door until she could get done washing the cups.
We went back to the office telling the story to our other friends. They too have their own stories to share. Well, the paranormal events are actually taking place right where we are. Some books were also giving me the information that the reason why ghosts like doing doppleganging or staying close to the living is because they are actually charging for an energy.
No one's actually playing a prank on me since I'm certain it was just me and my friend washing cups that time.
To Dan:
One guard did share his experience to me yesterday. He said he once saw a white lady standing beside the elevator door before in the ground floor. He called up to her telling her not to scare him. Since then, he never saw the white lady again.