The power cord of doom

I've been at my mom's house for a couple weeks now, and though there have been some noises at night, they've been the standard sounds. Nothing new.

Then Mom and I were discussing the stuff here, talking about how it got worse when the builder destroyed more forest to create another street for the neighborhood. Tons of new houses, and there's a dead end road like they plan to keep going, tearing down more trees and expanding beyond that new street. That new street went in around the same time as the thing on the bed, the doppelganger, etc. happened. We also discussed stuff my sister told me she'd experienced here (which includes hearing someone in the hall closet messing with stuff loudly, much like I heard when I was here about 10 years ago). 

We'd just finished talking about it when a power cord by my mother's chair whipped around and hit her ankle. I saw the top of it move (it was dangling over the back of her chair) and heard it hit. Her dog came screaming in to snarl and snap and bark at the air around her chair, and it took a minute to calm her down. 

We'd both assumed the cord was moved by her dog until we realized the pupper was in another room when that happened. When Mom looked around for the dog that wasn't there, she didn't see anything else, either. We have no explanation for the cord's movement.