Ghost image of Monitor 1 in Monitor 2 with wound together VGA cables

Question

In a custom-made special purpose cabinet, I have two LCD monitors connected to a single PC with VGA cables. Each VGA connector in the PC outputs different "feed". The cabinet houses multiple peripherals, so all the cables have been wound and tie-wrapped together through most of their lengths to keep the interior tidy.

I realized recently that a ghost/outline of Monitor 1 appears in Monitor 2 (like a kind of watermark). Disconnecting the VGA cable of Monitor 1 erases the ghost image in Monitor 2, but the ghosting still happens if I only kill the power to the monitor. If I replace the VGA cable of Monitor 1 with another cable that isn't twisted together with the others, the ghosting disappears.

The VGA cables seem quite cheap, so I theorized that the VGA cables interfere with one another because they're wound together. I'm far from an interference expert, though...

My two questions :

1. Is my theory correct? Can cheap VGA cables create ghosting images of one another in monitors if they're twisted together?
2. If possible, can you point me to a resource explaining (or could you explain) the basic working of VGA interference, as I couldn't find anything useful/readable.

Answer 1

It's a well-known phenomenon, known as Induction [Electromagnetic induction to disambiguate]

In short, any alternating current passing through a wire will generate a magnetic field, alternating at the same frequency.
Any alternating magnetic field will induce an alternating current in a nearby wire, of the same frequency.
The result is that the signals "magically" cross from one wire to the other.

This is the principle by which all old-style wire-wound electrical voltage transformers work, the basis of the electric motor and generator & also the basic principle behind microphone & speaker technology. The latter using the fact that once charged by the alternating current, the wire will want to move one way or another away from a permanent magnet, from which it can't escape.

Your 'cure' in this particular case, is to keep the cables away from each other for as much of their length as possible. Better cables may have better shielding, but the basic principle infers that distance is the solution.