Nissan Serena loose wires in rear brake light...

Question

I've had some electrical problems lately with my car...such things as my front and rear lights coming on when i press the brakes! I was advised to replace my rear brake bulbs and spray the lot with wd40. I did this this morning, and it appears to have solved the problem...but whilst rummaging around the light cavity i noticed 2 wires unstripped and unattached at one end in the left cavity and 1 stripped wire unattached at one end in the right cavity!..Any ideas why they are there...also in the right cavity is a white plastic connection? box where wires are fed in and screwed in place...there is one connection place empty..could this be where the loose wire that is stripped should be? I've been trying to find electrical diagrams for my car to no avail..Please help, many thanks.