Add large crown moldings along edges of beams and run wire in there. Stain crown to match the beams
Dorothy, PVC pipe. Aloha.
You can buy crown molding now that is specially made to hide wires. These can be put on the walls, beams, or along the ceiling. Also PVC pipe might be an asset in such a situation as yours if you paint it to hide it in plain sight. Hope this helps Dorothy