I would not play with this until I knew exactly why it was happening. You could easily be killed by an electrostatic phenomenon that is poorly understood. Remember in the old days when ball lightning would just straight up kill people by passing into them? Still does, but I think most people know better now than to touch such a ball.
The point is that they didn't even know what electricity was. If they saw a spark they wouldn't think, "Oh, high voltage", but rather "Must be supernatural, or a holy light"
Ancient people were not as stupid as you think. They knew that lightning was dangerous. More to the point, they knew that fire was dangerous--ball lightning resembles a floating orb of sun-bright fire, and any human will instinctively avoid such a thing. Historical phenomena later believed to be ball lightning were usually described at the time as "balls of fire." https://www.wikiwand.com/en/Ball_lightning
You're imagining that because they didn't know why something was happening, they were incapable of reacting to it in any rational way. You don't need a working theory of electricity to know that fire and lightning are dangerous.
