STAMFORD — An electrician working on a traffic signal was thrown from his bucket and left dangling above a busy Waterside street this week. Sgt. Andrew Gallagher said the man escaped serious injury because he was wearing a harness attached to the bucket when a cement truck struck his vehicle while he was hoisted 20 feet above the ground Tuesday morning. “Thank goodness the worker was following safety protocols and had his harness attached,” Gallagher said.