Why is aluminum wiring in a home dangerous?

When current is passed through a 10ft aluminum wire in a home, the wire can expand up to 3 inches. When the current ends, the wire can shrink up to 3 inches. This can cause wires to pull from electrical boxes and connections, as well as wear through their protective coating when touching parts of the house. Wires are typically hidden within walls and ceilings, and if connections are broken or wires become exposed, the electrical current can start fires.