I live in 100+ year old building in New York City. I’m installing a Caseta Smart Dimmer Switch, but there is no ground wire in the box. Everything is metal. My local hardware shop, with some really smart guys, said I should attach the ground on the dimmer switch to the bolt in the back of my light box. A friend said Ali could simply cap the ground wire and not worry about it. Is there any consensus about the best option? Thanks in advance.