My right side license plate light only works when the trunk is open. I thought it was completely out, but turns out when I open the trunk lid it's fine? I even tried swapping the lights to confirm and sure enough it's only out when the trunk lid is closed or almost entirely closed. I can seesaw the lid back and forth between almost latching and more open and it goes in and out. I've briefly spot-checked the cables running from the light, but I'm not good with that stuff. I don't really know what to look for. Any help? I'm willing to dig further, but I don't want to rip all the wire looming off when I'm not really sure where to start. Thanks!

 

The wire loom that goes down the left trunk support likely contains some wire that is damaged. Use a multimeter to measure that circuit as you move to trace the wire and identify where the damage is. That's really your only option