Harry Ackerman, head of the comedy division at Screen Gems, was taking ideas for just about any scenario you could dream up in the mid-60's. The studio had successfully transitioned from The Donna Reed Show & Hazel to the likes of Bewitched and I Dream of Jeannie. In 1966, the same year that The Monkees had joined Jeannie on NBC, there came a "modern fable" about a bachelor who pretends to be married in order to gain a promotion.
However, such a gimmick as what fueled Occasional Wife, in an era of wacky ideas in television, ended up failing, probably because there were too many wacky concepts. Michael Callan starred along with Patricia Harty as the titular periodic spouse. Harty would try again 2 years later, signing with Universal and King Features to adapt the latter's Blondie, co-starring opposite Will Hutchins, who'd flopped with Hey, Landlord for NBC the same year that Occasional Wife arrived. Got all that?
Don Kirshner, brought in along with the Monkees, was tapped as music supervisor for Screen Gems for a couple of years and is credited as such here, as well as on Bewitched, beginning with season 3. Along with the swinging theme music, one surprising hook in the series, as demonstrated in the pilot, is the use of baseball icon Vin Scully as the narrator.