RFI from electronic ballasts. this can and has caused problems for folks with neighbors. They get a shitty TV image, call cable co. and there's a knock on the door. Unfortunately, the problem is usually with the device. Some ballasts are quiet, some not. Lumitek can be either, some are some aren't. They put out interference and the power and lamp cables act as antennae. Sometimes this can be reduced by shielding the cable from ballast to the lamp. You can try foil around the cables and to a ground source. If this helps you may want to install a proper shielded cable. Good luck.