Many people keep their phone chargers plugged in even when they’re not being used, without realizing the hidden risks. For one, this simple habit drains what’s known as “vampire energy” small amounts of electricity that add up over time. Not only can this increase your energy bill, but it also places unnecessary strain on the power grid.

But the bigger danger is fire. Chargers, especially cheap or worn-out ones, can overheat if left plugged in, creating a real risk of electrical fires. Even if it doesn’t lead to flames, the constant flow of power causes both chargers and outlets to wear out much faster.