For those without smart TVs or Roku, but want to show video from computer to TV wirelessly:
Try the "ActionTec Screenbeam Mini 2" (~$50 +/- $5) or similar device. I have a SBM2 and it works great with my Dell Win 10 laptop and non-smart TV.
Search the web (or just Amazon or BestBuy) with "screenbeam" and you should see the SBM2 as well as other similar devices, some near $10, others hundreds of $.
The SBM2 does not require Bluetooth, but I'm not sure what it uses, maybe wi-fi or NFC. I'm not sure it works with earlier OSs or older computers that have been upgraded to Win10 -- contact Actiontec to check with them.
The SBM2 requires an HDMI input to the TV, and a power source (either 110V or powered USB port).
Also, my laptop can cast the laptop's 2nd screen to the TV while showing its 1st screen on the laptop -- great for showing a Powerpoint, or watching a movie (or security cam) while doing computer work!
I suppose 2 movies at once could be watched (each watcher with earphones), IF the audio could be directed separately. Hope this is helpful.
I DID encounter an older flatscreen TV at my church that would not connect with SBM2, but there was another TV of same model# that worked fine. Actiontec had no explanation except a malfunction of the 1st TV.