How can we fix this horrible problem?

My friend is being ually harred by an old lady. My friend is a young guy about 23 and his neighbour is well into her 80's. Anyway he told me that one day he heard a knock on his door, he went to open it and uit was the old lady wearing a trenchcoat and holding a radio. She turned the radio on and started stripping right there on his door step! She took her coat off and was naked. My friend says he screamed and slammed the door. He said the next time she came to his house naked witha vibrator and tried to be *ahem" y with it but she had a heart attack and he had to call an ambulance. Now she has taken to tapping on his windows at night and exposing her wrinkly old ***. What should my friend do about her?