"Personally, I’d just cover the bulb in a few layers of grounded chicken wire. But I’m cheap like that."

Shielding the bulb won't help when the switching PS in the bulb is making the house wiring resonate. RFI problems frequently fail to yield to silver bullet solutions.

You may try to wind a few rounds of the AC wires to the LED bulb on a ferrite core. That may (or may not) reduce RF bleed through AC.

(shrug) RF is hard.