Movie were lady sees guy outline on building and things

A young woman moves to a high-rise apartment building and soon begins to be tormented by an unknown stalker who seems to know her every move.

A filmmaker picks a "real" subject to shoot, and when she sees Guy on the street, she latches onto him. At first, Guy is enraged that someone is just following him around, filming, but soon he begrudgingly accepts her presence, then gets attached to the attention.