What is this ?

[Sport61]

20160702_133943.jpg 1934 vld . I need to find out what this is and does , what goes on this bolt with the nut ? Located where frame backbone meets the seat post behind rear head , above the tank shift rod lever. Couldn't find anything in the wireing diagram , trying to put the wireing harness back together dont know if anything's mising. Putting back what someone took apart years ago. Does a wire go on it ? Or what ? Thanks for any help . bad photo ,needs to be rotated to right.

[bselph]

I think it is where your tail light wire goes.It in effect splits the wire and that way you can take the wire loose if you have to take the whole fender off.