Old House Has No Ground Wires . This pipe will act as a ground and allows you to not have to drive a ground rod outside your house. I wired the ground wires from can light to can light. I have just installed a new gfci outlet for my landscaping lighting from www.justanswer.com An easy way to tell if a building is grounded is if the power outlets have two prongs instead of three. Check the local electrical codes and schedule inspections firstly. Attach the grounding wire now.