'91 CQ illuminated power window switch drains the battery

[Christopher Gharibo]

My '91 CQ's three power window illumination wire gets 9V even when the car is
off and locked. The switches work fine otherwise. The switch remains lit and
drains the battery. 

I've replaced the power window relay, door switch, thermofuse and the ignition
switch without any change in this behavior. I have the updated window switches
with the brighter illumination installed.

Any thoughts?