The Architects of Fear, directed by Byron Haskin.
A science fiction tragedy in three acts:
Fearing imminent nuclear war, a secret cabal of scientists plot to unite humanity by giving them a common enemy: an alien menace. Which will be faked but convincing, complete with spaceship and raygun.
Ok, that's a plan. It might work.
But who thought it was a good idea to turn one of their members into an actual alien through torturous transformations of mind and body, replacing all his organs and giving him new body chemistry and senses?
Didn't anyone suspect that this new being might be actually alien with incomprehensible thoughts and emotions, no longer part of their cunning plan?
Finally: a monster loose on Earth, his mission never to be accomplished, might our alien retain some core of his human past, love and yearning for his wife and unborn child?
This is one of the most memorable episodes. Maybe the effects worked better in the old days on small low-definition TVs where the horror of the monster-making procedures were less explicit, more suggested.
Robert Culp is our hero in the first of his three episodes. A prolific TV actor -- I Spy -- he also had a movie career -- Bob & Carol & Ted & Alice (1969), Hannie Caulder (1971).
His wife is played by Geraldine Brooks who I best remember at age 22 in Cry Wolf (1947) with Errol Flynn and Barbara Stanwyck. When young she much resembled later actress Natalie Portman.
Second acting credit for Billy Green Bush as one of the hunters. His first credit was in Stoney Burke the same year, made by the same people.
Notes:
According to the wikipedia some stations censored the alien "Thetan" as too horrific.
His encounter with the duck hunters inevitably suggests a parallel but comic scene in the later The Adventures of Buckaroo Banzai Across the 8th Dimension (1984).
Returning: director Byron Haskin and cinematographer Conrad Hall.
This is the first of three episodes by prolific TV writer Meyer Dolinsky.
On the Blu-ray the light commentary track is by Gary Gerani, who laughs at everything.