[RFI] Need a lightbulb photocell suggestion

[Howard Lester]

I bought a screw-into-an-outdoor-light-socket photocell in which you then
screw in a lightbulb. The photocell, of course, would keep the light off
during the day, on at night (or maybe during a total solar eclipse, too).
But the one I bought at Lowe's (I didn't note the brand) put out tremendous
nighttime RFI, at least on AM Broadcast, and that is entirely unacceptable.
Do any of you know of a good brand of these things?

Thanks,
Howard N7SO