What exactly is the law regarding packages sent to you that you didn't order (see details)

So, one day, two packages from UPS unexpectedly showed up at my side door. The outer box says they are Breville 800jexl Juice Fountain juicers that sell for $300—$400 each. I know this because I had been shopping for one of these online, but everyone was out of stock. All online merchants said the manufacturer was back ordered and I was unable to actually order one. I had in fact just purchased one at a physical retailer the previous day, having given up on online ordering.

The next day another showed up. Now this is weird enough, but here are the other strange things:

1) Only one of the three packages had a packing list.
2) That packing list said it was package #1 of 1.
3) That packing list had me listed as the ship to, but not the buyer.
4) I have no idea who the buyer is, just that they live in PA.
5) I live in MN.
6) None of my credit cards have been charged.
7) None of my bank accounts have been debited.
8) There are no orders on Paypal, eBay or Amazon.
9) I did not order these from the merchant who sent them.
10) I don’t even have an account with that merchant (I checked).
11) I have no emails from this company or any 3rd party.

So, I’m really not sure what to do, and I want to know the law here. I’ve always heard that if someone sends you something you didn’t order, you can keep it and don’t have to pay for it. Now, if within a reasonable amount of time someone from this company contacts me and says they want them back and will pay the shipping, fine…I’m not going to fight them, even if the law IS on my side, clearly this is some sort of weird mistake that resulted from my online browsing. But what if they don’t contact me?

I have in the past “done the right thing” even when I would have been in my rights not to, and it’s often been thankless and sometimes costly to me personally (I’d elaborate but this is already so long a lot of people won’t read it). You are welcome to give me your opinions on the right thing to do, karma or what not, but I’ve decided that if no one contacts me in a reasonable amount of time, if I am within my legal rights to keep these, I will sell them and pocket the money, but I haven’t 100% decided if and when I’ll say it’s time to get rid of them or if there’s anything else I should do to satisfy any legal requirements I may have. So, I’m wondering what is the legal standing here?

1) Is it still the law that if someone sends you something you didn’t order, you can keep it and not pay for it?
2) Is that still true even if it was an honest mistake on the merchant’s part and not some effort to rip me off?
3) Is that true even though I actually wanted and bought one of these things?
4) Is there a certain amount of time I’m legally required to wait before they become legally mine?
5) Is the keep it for free thing only true is the US Mail is used, or do the same laws apply to UPS shipments.
6) Does the fact that none of these was signed for impact the law?
7) Is the one with a packing list any different from a legal standpoint than the ones without a packing list?
8) Do I have any requirement to contact the company or the bill to person on the one packing list?
9) If I DO contact them, do I have any legal standing if they insist they shipped more than 3 (since no note was even left at my door by UPS, for all I know a dozen other ones could have been delivered and stolen).
10) Does the high value of this item impact my legal responsibilities or rights in any way?

I guess I am willing to do the right thing, I just don’t want to get screwed in the process, and in my experience, looking a gift horse in the mouth ends up getting you bit. I’m willing to elaborate on my thinking process in the discussion and I’m willing to hear anyone’s opinion, and I will take any advice I get under advisement…I’m not going to just dismiss anything I don’t want to hear. Yes, the money would be nice, but I don’t want to do anything I might regret, and part of that is making sure I don’t do anything illegal.

So, anything you can tell me about where I stand legally, your opinion on what I should do or what you would do, or anything else you can tell me that I may find useful, I’d love to hear it.