The two most common ways for me to remotely switch off lights at homes: using WiFi-connected smart bulbs and using WiFi-connected smart plugs. I use WiFi-connected smart plugs for TVs and some other electronics. I don't need to be on the same WiFi network to turn on and off the items except at time of set-up. There are some really interesting smart bulbs on the market, ones that let you change the color, brightness and other things; but what they don't let me do is turn on and off the rooms' physical light switches.
The major smart TV manufacturers have apps that work to change the channels, control the volume and such things.
My phones/tablets are my primary or secondary TV remote nowadays.