About a year ago, I had to lend my MacBook to a networking guy for a presentation and he created a peer-to-peer network on my Mac. The problem is I don't need it any more but my Mac keeps broadcasting it and it keeps showing up everywhere, on my Mac, on my Apple TV and all other devices. I can't find this network anywhere in the ad-hoc networks on my Mac and or the computer-to-computer networks. This is super frustrating and any help would be appreciated. I don't want an unprotected network with access to my laptop floating about. Here are some screenshots to show what I'm dealing with:
802.11 IBSS networks (often called “ad hoc” networks by many vendors, and called “computer-to-computer” networks by Apple) are designed to be propagated by any device that joins the network, even after the original device — the one that initiated the network — leaves it.
Your Mac is not associated to that IBSS right now (when you took the screenshot), so it is not propagating it. So some other device, in radio range of you, must have joined it at some point and is now propagating it. Go find that other device and fix it.