So I turned first to Mr. Google.
"They look some way like a shed or cabin, snug and rightly made, except the open door might could be a mouth, the two little windows could be eyes. Never you'll see one on the main roads or near towns; only back in the thicketty places, by high trails among tall ridges, and they show themselves there when it rains and storms and a lone farer hopes to come to a house to shelter him. ... The few that's lucky enough to have gone into a gardinel and win out again... tell that inside it's pinky-walled and dippy-floored, with on the floor all the skulls and bones of those who never did win-out; and from the floor and walls come spouting rivers of wet juice that stings. ... and all at once you know that inside a gardinel is like a stomach."
from "Come Into My Parlor" by Manly Wade Wellman, 1949.
Now as far as I can find, the Gardinel, (like the Flat and the Behinder) is not authentic Appalachian folklore -- it's probably Mr. Wellman's imagination at work. But it certainly has echoes of the alluring and deadly Gingerbread House that nearly did for Hansel and Gretel as well as Morgan Le Fay's castle of lard and other dainties that was set as a temptation for Wart in The Once and Future King. And, I realized, to some extent, In a Dark Season's house at Gudger's Stand (also in the standalone The Day of Small Things) is a figurative gardinel.