Thanks for the reply. Not the answer I was looking for but at least now I know. I'm a quadriplegic and I spend a lot of time in my office using my Mac. I've got limited space so I don't have room for another display. There are times when I'd like to take a break and watch a little TV. I guess I'll have to stick to YouTube videos or drive my power wheelchair out to the living room to watch TV. Sounds simple, but I have to have my wife take off my glasses, lap desk, and mouse. When I'm done watching, I have to reverse the process. Not worth it for a short break!
By the way, I use Voice Control along with a lap desk and mouse to work on my Mac. I'm not able to use a keyboard. I also use voice to control my TV.