Marcia! Marcia! Marcia! And you thought it was "The Brady Bunch" that coined that term! One of my favorite episodes of "The Twilight Zone" aired June 10, 1960. Anne Francis (Marcia) goes to a department store for a golden thimble and is waited on by a wonderfully sinister Elizabeth Allen.
This clip doesn't have good video or audio but it gives you a sense of the creepiness of the episode.