I can't speak for Alexa but our Roku is always on Fred Griffin Florida Real Estate .

We've never invited Alexa into our homes. We're monitored enough through our Ring camera and cell phones, we didn't want to make it too easy for "them".

The situation you describe @Fred Griffin, appears to result in loss of privacy.

"If you own an Amazon Fire TV or Firestick with Alexa support, there’s one important thing you need to know. First and foremost, do you believe your conversations with Alexa are private and confidential? Well, think again. Alexa is listening and saving all your conversations. Alexa is listening constantly to all the audio in your home. It records the conversations you have with her all the time.... a recent Bloomberg report showed that Alexa is listening to your conversations all the time. This is whether you use the command words or not. That means that Alexa is listening even when you aren’t communicating with her."

https://www.websafetytips.com/amazon-firestick-secret-alexa-is-listening/

Ah, the mysterious world of Amazon Fire TVs with Alexa—it's like inviting a friendly (or maybe overly chatty) neighbor into your living room, only to wonder if they’re secretly a spy. As for whether Alexa stays awake after you turn off the TV, well, here’s the scoop: most of these devices are designed to go into a low-power standby mode, not completely shut down.

So, unless your friend’s TV has a special internal battery (which I highly doubt), Alexa probably just “sleeps” quietly until spoken to again. Think of it like a very polite but somewhat nosy roommate who’s always on standby, waiting for the next “Hey, Alexa” to jump back into action.

Now, as for turning Alexa OFF—unfortunately, many of these devices don’t have a simple off switch. You can mute the microphone, which is like putting a gag on that nosy neighbor, but it’s not the same as unplugging or powering down. And, honestly, that’s part of the design—so it’s always ready to listen.

That said, I totally get the paranoia. I don’t have any spy devices lurking in my house—my computer, phone, and tablets are already enough to make me suspicious. I even tape over the cameras when I’m not using them because, let’s face it, I’d rather not have some clandestine agency like the NSA and other alphabet soup spy agencies peering over my shoulder while I’m binge-watching cat videos.

So, yeah, I’d say your friend’s spouse probably installed a device that’s always “listening in listen-only mode,” but it’s not actively recording unless prompted. Still, if it’s causing anxiety, the simplest fix might be just to unplug or disable the device’s microphone if possible. Better safe than accidentally becoming the star of some covert reality TV show, right?

So, we have two of those TVs also and have had that same question. We picked the brain of our electrician. There is no 'power' going to the TV, just stand-by and it is highly doubtful that Alexa can hear anything. 

The Alexa devices (Echo, Echo Show, Echo Dot, etc.) remain powered on at all times so, those are the ones that worry a lot of folks.

I do not know, nor will I ever know from experience.  I do not have "smart" spy devices in my home. 

My suspicion is even if one can turn Alex off ... it is never truly OFF. 

I have a tv that does not have Alexa. But it is a "smart" tv. Sometimes it turns on because it "hears" something in a nearby conversation. If it does not get a reaction, it turns off! Spooky!

I really don't know what the thing is capable of.

I can press a button on the control and it will go to Netflix or one of two other selections.

It is not an Amazon Fire TV.

My Alexa, a gift I've never plugged in, is in the same drawer as all the old cords mentioned this week.

I am in the fog on this one but have to wonder. As for Alexa, my wife said no, never! Happy wife, happy life.

Fred Griffin Florida Real Estate I am not sure since I got rid of Alexa so long time ago. I had her for a few months, we didn't know exactly how she worked. I would ask her to play classical music, but I found out, she was not a good woman, lol. Out the door she went, and I never want to see her again.

Sorry, Fred. I have no idea. We have no Alexa in our house or on our devices. My husband had one some years ago and gave it away.

I will never have an Alexa or anything like that.   Big Brother knows enough, doesn't need to know more.  I do have Smart Tvs, but they don't turn on by themselves.

Depends on the system.

I do not have Alexa or any device like it in my home.  I do have a smart TV and have yet to stream any paid app.  However, my Bose device comes on by itself at the same time every day and plays latin music.  I turn it off and it comes on shortly thereafter one time.  

Sometimes my ceiling fan in the main bedroom with a light comes on all by itself.  My electrician said it may have something to do with the energy in the neighboring condos.  W H A T?  This does not happen often only sporadically.