My wife's mother woke up in the night and "saw" a red-haired man standing in her bedroom staring at her. She jumped out of bed and grabbed something to defend herself with, but he was gone. It was a hallucination.
When my wife told me about this, I told her it was caused by Benadryl. She then told me that her mother hasn't taken any Benadryl in a long time.
Today, my wife reported to me that her mother had taken 4 Benadryls before going to bed that night because she was low on pain pills and needed help sleeping.