The Hebrew word behind "the dead" is* rephaim, *the shades, and it is not the word Sheol.
Quick answer
Drifting off the road has a destination, and the verse names it with an unsettling image: a gathering of the dead, and the man resting among them.
Read both lines
The verb in the first line is wandering rather than rejecting, which matters. Nobody in this verse decided against understanding; he strayed from it, which the book treats as the ordinary way people end up somewhere they never chose. Then the second line delivers the destination, and the two words do the work. Rephaim are the shades, the diminished dead, used elsewhere in this book at 2:18 for the paths of the strange woman. And the verb is rest, which sounds gentle and is not, because it means the wandering finally stops and the company he stops among is that one.
Why translations differ
Rephaim is not Sheol, and English versions render it variously as the dead, the departed spirits, or the shades. The catalog's settled position on Sheol applies here without change: name the translation issue, read the term as the realm of the dead as the ancient text understood it, and teach NO doctrine of final judgment from a proverb, in either direction. This verse is not evidence for anyone's eternal destiny and it is not evidence against any position on the question. It is a wisdom saying about where a life without understanding arrives, using the vocabulary its own world had.
Related: Proverbs 2:18 · Proverbs 9:18 · Proverbs 15:24 · Proverbs 14:12
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.