the egyptians had batterys...the romans had indoor plumbing....the hitties smelted iron.....splain two of three
Out of my area of expertise, but it's all there on the net for all to see....debates on when they were made, what they were, what they were for........
Even if they were a crude device that emitted a small electrical charge (and that's by no means proven or accepted) it defies logic to bring aliens into the picture.
I've seen loads of Roman plumbing. Good, simple design. Again, no need for little green men. (" We are from the planet Zork, and we bring you....plumbing!).
All respect to you PC but I think the alien atguement is the same as the God one - trying desperately to find things that science can't readily explain and using that as evidence of supernatural activity. But one by one they are broken down.