Origin of "guy" as an interjection substituting for "gosh" or "golly"?

In an episode of the TV show Ghost and Mrs Muir, the pre-teen daughter Candace has a line where she says,

Guy Grandpa, you sound like a grumpy bear.
[Guy being pronounced as rhyming with buy]

I personally remember as a child in the 60s, a very strict and religious family in our neighborhood that all said "guy" instead of "gosh" or "gee" so as not to be confused with saying God or Jesus in a way that would "take the Lord's name in vain". I stumbled across this thread in search of the origins of the use of this term after watching old reruns of the afore mentioned series on YouTube.

Green’s Dictionary of Slang dates the use of guy as a a euphemism for God from 1949. (US)

1949 [US] in DARE File (1986) : Guy! this bike stops fast.

1981 [US] Graziano & Corsel Somebody Down Here Likes Me, Too 211: All those things happen way back then was the road the Guy up there made me travel to get where I reached today.

The only instance of this usage that I had ever known of until I watched the clips posted by the OP was a series of young adult books by Kin Platt (https://en.wikipedia.org/wiki/Kin_Platt), Chloris and the Creeps (1973), Chloris and the Freaks (1975), and Chloris and the Weirdos (1978). These stories were set in southern California, and the use of "guy" as an interjection by one of the characters is pointed out in at least one of the books as a fad or affectation.