wrote:

www.google.com: amplifier glow

On my Canon 10D, I see that in the lower right edge on some long images.

The AG on my 10D shows up on long exposures as a patch of bright that
extends from the right edge to about ~15% across the image towards the
left. It dribbles away, not an abrupt transition. The OP's
description is consistent with this, but of course it is possible "real
light" is worming it's way in somehow. A weird lens flare?

Simple experiment: wrap the camera in some towels, put it into a dark
closet (preferably at night), and take a picture of the blackness.