When I had my HVAC system replaced a few years ago it came with a thermostat that had Wi-Fi capability. Since at the time I didn’t have a smartphone I didn’t bother to try to hook that up. I later noticed that when I check for available Wi-Fi networks there’s an unsecured one listed as “NewThermostat_498845”. I’ve occasionally wonder what would happen if I tried to connect to it with my laptop.
Typically, that is the generic name that it uses from the factory with a password that is in your documents that came with the thermostat. Once you connect to it, you would tell it to connect to your home Wi-Fi and then it would interact with Alexa or Siri and do fun other things.
ETA: These remote devices are great as you can do happy marital activity like when I am on a road trip turning the lights on and off. Yes, she is probably filing for divorce. 
While I did break down and buy a smart phone last year, I refuse to have Alexa, Siri, or anything similar in my home. It’s bad enough that I talk to my cats, but I’m not going to start talking to my appliances.
But Alexa and Siri are there to do your bidding. I love 
them. They both really try to satisfy my every whim.
I even have a mental image of Siri and Alexa. Siri wears glasses. 
We had to buy a new dehumidifier for our basement last fall. We didn’t buy the cheapest model, nor the fanciest, but we got a higher end one that included wifi.
I did not hook it up to our network, mainly because I can’t really think of a reason I’d need to (our dehumidifier dumps right into our sump pit, so an overflowing tank is not an issue). Also the wifi down there is spotty anyway so that makes it doubly useless in our case.
Wifi-enabled consumer appliances are notorious for creating security issues. I have so far avoided getting any of them. I don’t mean to threadshit though, so I will share a ‘why-fi’ story told to me by a penetration tester:
A small company with geeky staff bought a ‘Wi-Fi kettle’ for the staff kitchen. You could download an app for it and get notifications when it had finished boiling, change the colour of the decorative LEDs on the thing, etc. They put it in the kitchen and gave it the Wifi credentials for the office.
The office Wifi itself was secure, but the kettle created a vulnerability - all one had to do was to know the WiFi SSID for the office (easy to do) and broadcast an unsecured wifi signal with the same SSID, but at higher power - and the kettle would connect to it - this could be done from outside of the building.
Once the kettle was connected to the fake Wifi, it was possible to connect into it with a terminal, and list the contents of the internal file system, which included a text file containing the colour parameters for the LEDs, and the office Wifi password, in plain text.