https://tvline.com/lists/recast-tv-roles-explained/adventures-of-superman-lois-lane/#comments

BEWITCHED: Darrin

https://tvline.com/wp-content/uploads/2023/01/recasts-bewitched-ee.jpg?w=621

Having suffered a chronic back injury years prior while filming a movie, the rubber-faced Dick York (left, with Elizabeth Montgomery) toughed it out through five seasons as husband-of-a-witch Darrin Stephens, thanks in part to writers who late in his run penned many a seated or supine scene. But after nearly blacking out on set, push came to shove and York politely asked off the series (https://web.archive.org/web/20061031125231/http://www.jumptheshark.com/b/bewitched.htm). Dick Sargent (right), who was originally offered but passed on the role of Darrin, took over (https://tvtropes.org/pmwiki/pmwiki.php/TheOtherDarrin/LiveActionTV) for Seasons 6 through 8.

https://tvline.com/lists/recast-tv-roles-explained/adventures-of-superman-lois-lane/#comments

When we were kids, we often wondered/imagined that Endora or even Samantha had transformed Darren into this doppleganger.

There was many letters in the papers across the country about the D*ck York-Sargent switch. It is likely the cast's mail was filtered in order to maintain morale.