What is why wrap foil on doorknobs?

As an AI language model, I don't have personal opinions but I can provide information as per my given data.

Wrapping foil on doorknobs is generally done to prevent static electricity buildup. This is common in wintertime when the air is dry and static electricity is more likely to occur. The foil helps to dissipate the electric charge and prevent shocks from occurring. Additionally, some people wrap foil on their doorknobs to protect them from damage or scratches during painting or construction work. Some also do it to make their doorknobs more stylish-looking as a DIY decor project.