What legal rights do you have to keep something mistakenly delivered to you?(LONG)

Several states (NV, WA, MDhave similar statutes, but all have statutes against theft, which this is.
http://www.crimesanddefenses.com/SilverBullets4.html
*Larceny of misdelivered property: What about situations where property was misdelivered based on a unilateral mistake, e.g., the cleaners mistakenly but willingly misdelivered V’s suit to D? Larceny occurred when D realized that possession of someone else’s property had been delivered to him and D took delivery anyway with the intent to keep the property suit and permanently deprive the owner of it. The legal view was that when the transferor acted under unilateral mistake of fact, delivery of the chattel was ineffective to transfer right to possession; if the transferee, knowing of the transferor’s mistake, receives the goods with the intention of appropriating them, his receipt and removal of them is a trespass and the offense larceny. On the other hand, if there is a mutual mistake, e.g., D thought the suit was his when it was delivered to him, and the recipient is innocent of wrongful purpose at the time of his initial receipt of the property, its subsequent conversion by the transferee is not larceny. *

http://www.law.newark.rutgers.edu/files/u/Thieving%20and%20Receiving.pdf
*The Model Penal Code formulation, in fact, is doubly redundant. A
separate theft provision, Section 223.2, entitled “Theft by Unlawful Taking
or Disposition,” says that “a person is guilty of theft if he unlawfully takes,
or exercises unlawful control over, movable property of another with purpose
to deprive him thereof.”31… proof, with, and subject to same penalty as, theft by unlawful taking, … theft by extortion, and theft by failing to return lost or misdelivered property)./I]

You got off easy.

A couple of years ago, UPS left a big box on my porch with only a scrap of the label to indicate that it was destined for my street. It wasn’t something I’d ever have ordered, but I wasn’t about to keep it. I opened the box, hoping to find an invoice indicating the buyer - no luck.

The shipping label was in bad shape, but I was able to make out enough of a name to figure out that it was destined for a neighbor about 4 houses down. Lucky for me, they had an unusual name, so matching it to the property records on line was easy. I wrote a note so they knew why their box was opened and left it on their porch. Never heard back, so I guess it was theirs.

As an aside, I’m not anti-social, but we live in a very spread-out neighborhood and we rarely see anyone - even the couple right next door. Everyone here seems to keep to themselves.

There have been a few news stories where a roofer goes to the wrong address and goes to work on the roof. Anyone recall how those cases end up?

A case like the OP’s makes me punchy. Sure, the TV got delivered by mistake, the guy’s not going to take it back himself, he’s not going to call, maybe they’ll never come get it. But when the owner calls him and tells him it was delivered by mistake and the guy says “No, it’s mine now!” then he’s being a huge asshole. He knows it’s not his, and if he’s stupid enough to believe he’s got a legal right to it then too bad shit-for-brains, it ain’t yours, give it up.