Sandra Price, 66, is accused of sending a series of "offensive" and "intrusive" letters to the actor's Norfolk home.
Shaw told King's Lynn Magistrates' Court that Price also forced him to listen to a 45-minute cassette that she prepared.
"It was quite hard listening. She said her life was a living hell and it was because of me, that she was in great pain," he said. "Only she understood what my pain was and only she could help and heal.
"It went on along these lines for a good 45 minutes. It was repetitive... I can't characterise it in any other way than by saying it was spooky. She sounded unhinged."
Price, who was seen hiding in a ditch near the star's home, also left him a file that detailed his career.
"It referred to happenings in my life, places I had been, movements and so on. It was a very complex dossier on me," he said. "I felt that this woman was unbalanced."
Price denies harassment. The trial continues.