NanKate I had this happen when I changed tv sets. One time I was woken in the middle of the night by male voices downstairs, and I lay in bed holding my breath, trying to decide what to do as I live on my own.
But as I tiptoed to my bedroom door to lock myself in, I realised that the male voices were quite educated and were discussing Brexit. Further listening confirmed that it was a political discussion so I was brave enough to go downstairs and unplug the tv.
Now I turn it off at the socket every night. I appreciate this doesn't help you as you want to record programmes, but all I can say is that you're not alone with the spooky tv voices.