It can't turn on if you you turn off the power via a switch at the outlet, and it's very unlikely to turn on if you turn it off via on-off button on the TV itself. Don't leave it in pause during the night, just turn fully off.
I have a 55" Samsung 4K TV (Samsung QE55Q6F) which I have had for around a year. I originally fitted a Denon soundbar to it with HDMI and optical connections. It all worked perfectly. Recently the soundbar developed a fault so I decided to replace it with a new soundbar. I bought a Sony HT-CT290 and connected it with just the HDMI. All fine for 2 or 3 days and then the TV started turning itself on during the night. Took some advise and was told that it needed the optical connection. Have done that and again for a couple of days all was fine but it all turned itself back on during the night last night. Anyone got any ideas??