I think this guy is following me?

Everyday I go to work, I see this guy, I think he follows me. I never heard of him working so I don't think that's likely. He just sort of stares at me blankly, straightens his tie then walks off. I tried to follow him once, but he went behind a door, which was then locked. I see him looking at me from catwalks and windows. It's creeping me out. He looks like one of those generic people, just wearing a suit and carrying a brief case. Maybe he is some kind of gman (government worker)?