So my toddler has a woodblock puzzle. When a piece is put in place, the small magnet on the back of the piece triggers a circuit, which plays a sound (ambulance, jet plane, motorcycle, etc.).
When I turn off the light in the family room at night, if the puzzle is sitting out, the circuit will trigger. What would be causing that to happen?
Try throwing a heavy, dark blanket over it. If it still happens, it’s something to do with light, if it doesn’t, then it’s likely EMF from the light. I’ll bet the light is LED or CFL.
You could also try bringing it to anther room with a different type of bulb, preferably incandescent, and see if you can repeat it.
Also, just to confirm, this toy runs on batteries, right? It’s not plugged in.
Are you sure it’s a magnet triggering it in the ordinary course of operations? Maybe the spot for each piece has a light sensor behind it, and it’s actually reacting to the piece covering the light.
I listened to a podcast interview with the founders of Melissa & Doug, makers of children’s puzzles, and the topic of “haunted puzzle” complaints came up. Even they seemed fuzzy on the science of the issue, but said it was just certain puzzles in a certain environment that caused the sound to activate when the lights were turned off. Fluorescent lights do weird stuff to radio frequencies.
Now that I think about it, I remember my (ex) FIL mentioning that if one of the baby toys was in just the right spot in the house, the furnace kicking on would trigger the toy to do whatever it did.
My kids had a cookie monster doll that would say “cookie” when it was picked up. One day, I am alone in the house silently reading a book. I hear “cookie” from the toy box on the other side of the room. Very creepy.
When I lived with my parents we got a talking Shrek from McDonalds, but it was low on battery and instead of saying whatever it was suppossed to say it said, in a slow, creepy, slurred voice something that sounded like “Veroonicaaa”.
It was very funny (for me) because “Veronica” is my sister’s name, she got seriously creeped out.