What you have here is a spoofed Mac address of an internet enabled device. I assume you have already tried turning off your devices to make sure it's not something simple. Stating the obvious, but DO NOT click the button to give the device access to your network. Be sure to turn off GPS, wifi, and Bluetooth from your phone in case something odd is going on.

Does this device follow you, as in does it try to connect both when you are away from home and when you are at home? Does the Mac address change or stay the same?

The following is all purely hypothetical because we simply have no information about this supposed device. It could be malicious. It could be something else.

Thinking outside the box here... I find it a little strange that it is trying to connect to wifi. If this device was a pre-made tracker, it wouldn't have much need to connect to wifi. I looked up the most recommended trackers, and they all use 4g, not wifi. I can see a less reputable manufacturer adding wifi capabilities because they use the cheapest parts possible, but more likely, if what we have here is indeed a tracker, it's not a typical tracker.

The other thing we have here is that these trackers have batteries. They need to be charged every 10 or 20 days. So assuming this device is not hardwired to your vehicle, if you brought the vehicle to an isolated place (say a friend's garage whom you trust and is not crazy), then left it there for a month or so (could even disconnect the battery if it made you feel better), you could theoretically kill the battery on the device. Start your vehicle up and see if it tries to connect again. If it doesn't, congratulations. If it does, it's probably hardwired.

The best thing to do here is to bring it to a shop and have them look for a tracker. I remember seeing a comment previously about a popular shop that does free tracker inspections, but I do not recall the name. Show the shop that the device shows up as trying to connect, and let them go nuts.

Someone else mentioned using kali Linux on a live USB to gather some information about the device. This probably isn't a bad idea if you are tech savvy or have a tech savvy friend. You could at least get more information about the device such as the OS it's running and IP it uses. Then you could go from there.