Paul's security team were left shaken as the man drove into The Beatles legend's Peasmarsh estate, in Sussex, screaming, "I must get to him."
A source told Britain's News of the World newspaper: "It was terrifying. This guy put the fear of God into everyone because they thought he wanted to kill Paul. This was the most frightening incident they've ever had at Peasmarsh."
"Everyone was terrified that the guy could turn nasty. No one knew if he was armed."
Security guards managed to stop the man reaching Paul's home by activating an emergency gate, but only after he had managed to get within yards of Paul's house.
The intruder who fled before police arrived on the scene was arrested after a three-mile high-speed chase.
The man has now been sectioned and detained in a local psychiatric hospital.
A police spokesman said: "We received a call from a security officer at Peasmarsh and later arrested a man at his home address. He was initially arrested on suspicion of criminal damage and failing to stop when challenged by police."
"He was later detained under the Mental Health Act and is not facing criminal charges."
Paul, 64, was not at home when the terrifying incident happened as he was having lunch locally with friends.
Fellow Beatle John Lennon was shot dead outside his New York home in 1980 by crazed fan Mark Chapman.
The late George Harrison narrowly escaped death after being stabbed in the chest by a fan who broke into his home seven years ago.
