No smart TV or Alexa Here.
That said, I usually do not turn off my cell phone.
Would wrapping the cell phone in tin foil help?
How about alternate layers of tin foil and wax paper, like a capacitor? Ground the foil?
You can buy a Faraday case for your cell phone for around $10 on ebay. I bought one for my tin-foil hat wife for her phone. When she puts the phone in the Faraday case nothing goes in or out. No phone calls or text messages until the phone comes out of the case. It works great.