> Anyone have any advice?

Microchip have a circuit, much criticised, which supplies mains
directly to a PIC through a resistor

A capacitive dropper would be OK, using the filament in the
return path

IOW, the 5V device is in parallel with the switch + filament

http://home.clear.net.nz/pages/joecolquitt/txless.html

Estimate what current your 5V device uses to calculate the
capacitor value, based on 70mA/uF. Cold resistance of the
filament would be a few 10s of ohms

Joe
--=20
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.