This is a test of commonsense. Complete the next sentence:

How to test spark plug wires
Check for symptoms.
Defective spark plug wire leave tell-tale signs of their deterioration, including :
An erratic idle engine misfire radio interference decreased fuel mileage failed emissions tests due to elevated hydrocarbon emissions or a fault code indicating cylinder misfire. Check engine light
Inspect the wires.
Use a flashlight or an area with good lighting to perform a visual inspection of the spark plug wires. Look for physical damage to the wires or boots such as cuts and scorch marks.