WAS STEPPING FROM 3RD STEP TO 4TH STEP ON 8' LADDER & LADDER MOVED. EE FELL & HIT HIS HAND & ARM ON TRANSFORMER. HE HURT HIS RT INDEX FINGER. WENT TO HOSPITAL, IT WAS OUT OF JOINT. PLACING CONDUIT IN LIGHTING PANEL & PULLING WIRE. WAS USING A STEP LADDER TO DO THIS. HAD GLOVES & SAFETY HARNESS ON.