When she runs an extension cord into the house and plugs it into a non-GCFI circuit, the treadmill works fine.
Extension cord from one area to the other is a no-no.
There is a safety barrier between areas.
Don't break it.
Hey, what can I say? She's a software engineer. ![Confused :-//](https://www.eevblog.com/forum/Smileys/default/confused0024.gif)
If PE is connected through and through the hole in a barrier is much smaller.