So Bill Bixby hosted a kid’s show on PBS in the early 80s (‘Once Upon A Classic’), that much I know.
However, I cannot find the title of one episode about two boys that found an alien ‘moon ball’ – a shiny silver sphere that would follow them and try to communicate with them. It was an adaptation from a book (and I remember reading the book, too! The alien was glowing and fuzzy in that!) but Google is failing me when I try to find the title of either.