[RFI] Noise changes when room lights turn on / off

[KD7JYK DM09]

Have you tried killing the main breaker to your property?  That could help 
rule out things on your end.  There are "ghost" currents from things running 
while "off", a lot of household electronics to this for clocks, soft-start, 
memories et cetera.

Do you have a little pocket AM radio?  You can tune to one end or other of 
the AM broadcast band, then crank up the volume, walk around the house and 
move it to within a few inches of electronic/electrical devices and hear the 
sounds they generate, even when off.

Something interesting to note...  A friend and I were at Starbucks the other 
day.  I had my radio scanning the GMRS freuencies (UHF) and the squelch 
would break on one frequency with white noise.  I turned up the squelch, it 
broke again.  I moved the radio about 6" away from her purse, problem 
solved.  Her phone was in her purse, although not being used, still somewhat 
active and generating RFI.

Kurt