A device called a(n) fuse keeps too much current from flowing through wires. The fuse prevents wires from heating up and starting a(n) fire. There is a strip of metal inside a fuse. This strip is a(n) resistor. The resistor will melt if there is too much current flowing through the strip. New homes have a circuit breaker or switch to protect circuits. If a dangerously high current flows through the circuit, the switch opens. A spring holds the switch open, creating a(n)open circuit. If there’s a short circuit, the switch will be in the off position.