I have a GFCI outlet on top of my pergola outside that had solid 3-conductor wire ran from there to an outlet on the other side of my patio when my parents built the house. My Mom wants me to put some decorative exterior lights on top of the pergola, so we bought a strand but they have a 3-prong plug. Although the GFCI outlet has a ground connection, it is not actually hooked up where it plugs into the wall. This is because when my Dad ran the cable and he used a very heavy gauge solid core wire. Unfortunately, when I went to terminate the cable into a 3-prong outlet with screw terminals, the wires were so stiff that I could not get the ground wire connected to the screw terminal (I put one of those stickers on the GFCI outlet indicating it is not grounded). I've attached a photo for further clarification.
My question is; do I need to connect the ground for the lights to operate safely, or is it good enough that they are connected to a GFCI outlet?
I think I'm going to end up going with Harper and RME's solution with the pigtail. I can confirm that the outlet DOES WORK without a ground connection, just an FYI. I'll install the pigtail this weekend maybe when it's not so hot outside....