Yes, you need a special electrical box to install a ceiling fan. A ceiling fan is heavier than a light fixture and requires a special electrical box to safely and securely support its weight and movement. A standard electrical box is not strong enough for a ceiling fan installation and can lead to safety hazards and ceiling damage. The recommended electrical box for a ceiling fan is a fan-rated box, which is specifically designed to hold the weight and movement of a ceiling fan. Using the correct electrical box is important for a safe and stable ceiling fan installation.