The link has a ton of information.
Now, It is obvious that putting it completely offline is more safe. But, some people often use the TV’s to watch Netflix or something like that. Then they might forget that it is still connected to the internet when they are done watching.
Under Privacy Settings, there are options for Device Usage Data, Collect App and Over-the-Air Usage, and Interest-Based Ads. All are enabled by default, but you can disable them.
This is the reason I have a 20+ year old plasma TV. Absolutely nothing smart and still somewhat thin. Also the picture is sometimes better for movies because of how it handles blacks and contrast.
Burns more electricity I guess. But most plasmas should be around the time of the flat TV crazy started before LED took off. Before they started making them cheaper by stuffing them full of spy software.
You can get a smart TV and set ut up without Wi-Fi. You can do that on Google TV, Tizen and WebOS. You will have to turn off the eco mode and motion smoothing so it is not dim and blurry.
Do you have some TV box connected to it? Like Nvidia Shield, Apple TV 4K, Chromecast Ultra, Roku, Fire TV or some Linux box?