electricalextension-cordoutdoor
I have a Christmas lights setup where one extension cord has its ground socket empty and facing upwards.
Do I need to worry about rain water potentially getting into the open ground socket? If so, would covering the hole with electrical tape be an appropriate fix?
You want to get these blackout caps.
I'm not sure why the wires would be exposed to the elements, however if you want to seal them, wrapping in electrical tape and tie wraps is definitely not the right solution.
I would utilize heat shrink tubing:
Thin wall heat-shrink tubing is great for cable insulation, marking or bundling, with superior mechanical, abrasion and moisture protection
Basically you slip this over the entire connection and then use a heat gun to shrink the tubing tight against the connections. It's a cheap and effective way to protect electrical connections.
Best Answer
You would do well to pull some slack to that extension cord and arrange the plugs so that they at least face down. It is not just the GND terminal of the extension cord that is of concern. You also have the open prong holes on the stackable Christmas tree light string that is facing up.
Water that gets into the electrical plug contacts raises the most concern that it can and will lead to corrosion on the metal contacts.
I have found that a better overall solution is to arrange the Christmas light installation so that plugs and extension cords are terminated up under the roof overhang.