A lightning rod on the roof of woodland mansions

I want woodland mansions to have a lightning rod on the roof. I want this because they are highly likely being stuck by lightning during a thunderstorm and burning down, before the player can reach the top and place a lightning rod on his own. I want it done by adding a single lightning rod on top of the structure "woodland_mansion/roof" so that there is one lightning rod ("woodland_mansion/lightning_rod") on the entire roof.