@JovanHPulitzer @BruceLei3
Also - if I were a bad guy I would have wired an AV500 (ethernet over power) unit inside the actual machine. Is there a scanner to detect this? They could have an uplink in another room or closet and you would never know.

FLOATvINT  (@FloaInt) January 5, 2021

So in the context of securing a site (say polling station) - is there a device that can be plugged in to the AC outlet to detect or jam/block ethernet over power?
TIA

Plugging it into a UPS would almost certainly prevent the signal from getting as far as the wall socket.  A UPS is probably a good idea to make sure it doesn't lose power - any concerns about ethernet over power are likely groundless, but would be alleviated by this in any case.