Short story similar to "Sir Gawain?"

I remember this story from an elementary school book. Here’s what I remember:

A man is searching for someone who will keep his word. The test: He will allow anyone to cut off his own head. Then, he will return a week later, and cut off the other person’s head. If the other person agrees to it, there is some great reward (which I do not remember).

The guys in the taverns say “No problem!” After all, once the guy’s head is separated from the body, how the hell’s he gonna come back.

Well. . . . The first person chops off the head, after which the man’s decapitated body calmly walks over to the head, puts it back on, and tells the guy “OK, I’ll be back in a week to make sure that you live up to your end of the bargain.”

A week later, the erstwhile ersatz headsman is nowhere to be found.

This continues until he finally finds someone who does stick around to put his head on the chopping block. But no decapitation occurs. The man was simply looking for someone who would keep his word.

Any ideas???

whatcha doing man, you know i’m stoned…right?

No clue. But if it was from elementary school, there were a bunch of “ghost story” books by the same author (whose name unfortunately eludes me at the moment) that were popular about 11 years ago. They had a lot of UL type stories, the traditional ghost stories, and I could imagine the Gawain-like story being in there. This probably doesn’t help much, huh? Well, free bump anyway.