My daughter had an intercom in her room until she was about 5. It was useful for her to shout me up the stairs.
Anyway.
When she was little.little she had a toy bear with buttons on the front that played music when you pressed it.
I'd hear it sometimes in the night and assumed she'd rolled on it or woken up and was messing with it.
She put grew it eventually but didn't want to throw it away. So I took the batteries out and put it on a shelf with a couple other not played with toys. She can reach the shelf, but it's a stretch so she doesn't tend to bother.
She gets to about 5 and we're sat watching TV one night and the lights on the intercom flash up to Red, I get up and turn the volume up, we can hear the bear...
The bear with no batteries..
the bear with no batteries on a shelf she doesn't mess with..
I'm a bit weirded out at this.
So I say to her,
"Have you been messing with your old bear toy?"
"Not me, Lilly has though"
"Who is Lilly?"
"She's the girl that visits sometimes. She's used to play with that bear when I was asleep."
"Oh. I see...."
The intercom was gotten rid of the next day and we put the little bear in the loft with some other toys and a little Frozen Foam chair for Lilly. My daughter is 10 now, she doesn't remember Lilly, but I'll not forget.