Regular GFI and downstream duplex recept in bathroom.

Christmas candle - 7 1/2 W - in the window - ungrounded plug type with in-line switch plugged into the GFI.

Wife has hair dryer with GFI cord termination plugged into the duplex.

Turning on or off the candle with the inline switch trips the GFI on the hair dryer - but never the wall mounted one. Push the reset button, and all's well.

I don't understand..... Explanation?

Grov