So I'm looking to see where to install a new switch for auxillary lights when I find behind a blank "dumby cover" a wiring harness for something to be plugged into there. (This the top left blank in the cluster of push button switches). What's this for and what can I plug in? Please don't tell me its pre-wired for roof lights. I already wired those and broke my windshield in the process. 
Thanks in advance for your help.
Sincewrely, Ned

Thanks in advance for your help.
Sincewrely, Ned