Ruth Montgomery
was one of the first channels and authors to discuss the ” Walk- In Phenomenon”. “Strangers Among Us ” is not available on PdF but I would see if you can get a used version on Amazon or a used bookseller. My feeling is that a Walk- In is a Soul exchange when a Soul no longer wants to be here but the Soul is part of the Born in Soul’s Monad or Soul Aspect. I do not believe that there is a totally unrelated Soul coming in….yes they may be a different personality and it is only with an agreement between the Soul leaving and the Soul coming in…otherwise its possession and that is against Universal Law.
She was one of the first authors to help us understand the Real History of Earth and where we are headed ” The World Before” talks about the Real History of Earth.
……this book is about our potential future.