An r/knives post this weekend came with the kind of caption that guarantees engagement: "Found this knife in one of the houses I do showings at," followed by "Little scary lol." The photo shows a long clip-point blade with a wooden handle and a guard, the sort of shape that reads as either a vintage hunter or something a prop department would buy.
The replies were immediately unhelpful in the way comment sections are. One called it a "copper heist / harvesting tool," which the original poster cheerfully accepted. Another said he would "almost call that a shiv, but the blade's a bit long." Nobody identified it, which is the honest outcome: without a maker's mark, a long clip-point hunter from an unknown shop is nearly impossible to pin down.
The actually useful discussion, buried under the jokes, was about what a person should do in that situation. A knife in someone else's house during a showing is not a find — it is property, and the correct move is to leave it exactly where it is and mention it to the listing agent. Picking it up for a photograph is a small risk most people would take; pocketing it is a much bigger one. Several commenters made that point more bluntly than the original poster expected.
There is also a collectors' angle worth drawing out. Long clip-point fixed blades with wooden handles and brass guards occupy an odd corner of the vintage market: too plain for custom collectors, too old for tacticool buyers, and often worth less than the shipping cost even when they are decent knives. The valuable ones have maker stamps — Western, Marble's, Case, KA-BAR — and even then, condition rules.
Verdict: a fun thread that doubles as a reminder. If you find a knife in a house that is not yours, take a photo, leave the knife, and tell the agent. The internet will happily speculate about what it is, and none of that speculation is worth a theft allegation.