Dig the trench for the electrical lines. Start with the corner that the electrical light is coming from. Go slow and steady. It is better to dig by hand if you are digging next to the house.
Before you begin any excavation you need to call and check for the location of your underground utilities. In North America, One Call Referral Services can connect you to the national directory of utility companies.
Use a smaller stone to hold the top up so you can make any adjustments before setting in place. Remove the small stone and center the large stone on the pillar.
Connect the light with one electrical line coming through the center of the top stone. Strip the wires and connect the ground, neutral and hot wires together. Black to black, white to white and ground to ground.
As with any electrical project, safety should be your primary concern. If you are not 100 percent comfortable with making an electrical connection yourself, please contact a qualified electrician to do it for you.
Attach the light to the flange in the center of the cap stone. Lay the electrical line in the trench and cover it with dirt.
Note: Direct burial non-metallic sheathed cable (wire) was used in this example, so there was no need to run a conduit. Always check your local codes.
Turn off the power to the circuit that the outside light switch is connected to. Unhook the switch from its box to give you room to work. Connect your grounds together -- the white to all neutral wires, and the black to the switch leg side, opposite the wires on the switch. Put everything back in the box and put the cover plate on.