Actually, this results from house electrics already. When you have a typical unbalanced AC line, you get a "hot", "neutral" and "ground", and those go back to the main breaker panel. What the noise sounds like is that the modular is trying to ground itself to a different circuit, ground-wise. So what's going on is that the other AC circuit is flowing THROUGH the modular and getting into the audio, probably through it being connected to a mixer, etc that's on a different circuit than it is, which allows the AC into the audio.
This doesn't happen much in Europe, because European (and a lot of other) power systems provide BALANCED power. There's no "neutral", but instead you have two legs at 1/2 of the total mains voltage that are referenced to ground, which gives you the proper 230V for the device in question. But with OUR goofy power (and anywhere else there's unbalanced AC), that "neutral" and the associated ground line can provide a path for groundloops if you don't have either isolation to kill the loop or don't have a proper star ground. Sure, you can have balanced AC in the USA as well...but it's on YOU to put in the balancing toroids (imagine a 40 lb bundt cake...now imagine several of them, one per circuit). Very messy, expensive, and labor-intensive.