Out of curiosity, what method are you using to ground yourselves while you sleep? I assume you aren't sleeping on a roost with a length of grounded speaker wire attached. ;)
That is also when the light left. Wait until they moult in the fall and rerun your experiment. They will naturally be laying more now simply because of the increasing light. Commercial egg factories provide 14 hours of light per day to keep the hens laying through the winter.
Or be really...