First of all, it is a great misconception that electricity flows to ground. In fact, a ground connection is not even required in order for electricity to flow. Generally, electrical current flows to it's source. And while the electrical charge is circular in flow, the energy is not. When a lamp is turned on, the charge is literaly "wiggling" back and forth through the conductor without much travel. A single electron may only move a centimeter an hour. The effect of this charge at the lamp is heat and light. So in effect, the electricity isn't going anywhere. A potential is established and utilization equipment is connected in between. All the charge that is available in the conductor will always be there and is not entering and then leaving the wire. This probably didn't clear things up, and it most certainly won't assist explaining the theory of current flow and charge to a child. Good Luck!!