I was there. That’s the citation.
"The Munsters"
Season 1, Episode 18: "If a Martian Answers, Hang Up"
Herman contacts by radio a "Helosian" from "Outer Limits"
Continued till the end of Season 2
"My Three Sons"
Season 7, Episode 17: "You Saw a What?"
No one believes Ernie when he says that he saw a flying saucer.
Continued till the end of Season 12.
"Gilligan's Island"
Season 2, Episode 9: "Nyet, Nyet, Not Yet"
Two Soviet cosmonauts land on the island, way off course from their target.
Continued till the end of Season 3.
"The Wild, Wild West"
Season 2, Episode 6: "The Night of the Flying Pie Plate"
Series continued till the end of Season 4.
That's just a small selection, disproving your "impression."
Regards,