Long needle-nose pliers are a vital tool in an electrician's tool kit. They have a long, thin nose, designed to grasp and cut wires in tight cramped spaces that are impossible to reach otherwise. Needle-nose pliers are made of special forged tool steel, and they have insulated plastic-coated handles that provide a firm grip and protection from electric shock. Not only electricians find these pliers to be a handy tool; long needle-nose pliers are also used in crafts projects and jewelry.
Electrical wiring in switch boxes or outlets usually can't be accessed with fingers or unwieldy tools. Changing a spark plug fits into that tight-spot category, and needle-nose pliers are very useful if you need to do just that. Spark plug boots are often difficult to remove; they require a twist-and-pull motion that isn't always possible to do with your fingers, and sometimes there are electric wires that get in the way.
First things first: Wait until the engine cools, and never attempt to fix more than one spark plug at a time. If you don't have spark plug pliers, you can use needle-nose pliers to grasp the spark plug boot firmly, twist with a firm grip to loosen and then pull to release. You can use needle-nose pliers in small places to reach inside as an extension of your fingers, and you can use them to gently pull out the spark plug wires to check them. Some wires inside the cap are held by spring clips, which needle-nose pliers can grasp and move. Repairing damaged spark plug threads is intricate work that necessitates use of long needle-nose pliers with a narrow, easy grip.