I've shielded and stargrounded both my Strats and with the Lace Sensors they were dead quiet. Two months ago I moved nearby a railroad. The place where I'm playing (inside the house, of course) is about 30 meters away from the railroad's powerline; is it possible that the hum I'm hearing is caused by that powerline ? And that - somehow - the Lace Sensors are influenced by it ? I'm not sure what kind of powerline it is, but I suspect it to be an AC line, as the voltage is indicated to be 25k.