[Amps] RFI Question

[K6QD]

I don't know if this is the correct forum for my question, so if not, I apologize.
I have a friendly neighbor who has recently installed new light dimmer controls on three lamps.  I am causing his lamps to go on & off when running any power over 100W on all HF bands.  I had not seen this type of dimmer before, but it is a small (2" x 2" x 3/4") plastic box with 4 leads exiting.  The 4 leads go to 1) 115 hot, 2) 115 neutral, 3) 115 to the lamp and 4) control lead to the metallic base of the lamp.  By momentarily touching the lamp base one can set the brightness to 3 levels as well as off.  Opening the box, I find one IC (8-pin mini-dip), one TO-220 (appears to be a pass transistor - nomenclature: "BT136", "600D") and multiple R, C & diodes on a single-sided PCB.  There is no reference to the manufacturer other than "China".  I can generally understand how the device works even though I cannot reference what the IC is.  The IC nomenclature is "DI-2417" & "C4841917-6A".  Has anyone had any experience correcting an interference problem with one of these type devices?  Thanks!   Mike K6QD