Does anyone remember the narration?Which episode was the first one to use that gimmick,and which was the LAST to use it?

The first episode had narration don't remember the others, other than during a two parter.

That was movie actor Jose Ferrer doing the narration - which lasted for three episodes: "I, Darrin, Take This Witch, Samantha", "Be It Ever So Mortgaged" and "Mother Meets What's His Name".