It's not an iron mesh base that's supporting the mattress on the bed is it?
There was a recent article in New Scientist where they stayed in the supposedly haunted Tapestry room in Muncaster Castle, Cumbria.
The scientists doing the study think that magnetic fields could be to blame and they found the strongest magnetic field in the room came from the iron meshed bed. It fluctuated when people turned over on it as well.
They didn't see anything that night though. 🙂
I think the only way to be sure is let the lad sleep with his mum for a week and you have his room. 😀