What is the best type of bit to use for drilling into an attic to wire a keypad?

Using a flex bit is the most suitable choice for drilling into an attic to wire a keypad. Flex bits are designed specifically for navigating through tight spaces and around obstacles, making them ideal for installations in areas like attics where access can be limited. The flexible shaft allows the drill bit to bend and maneuver around structural components, such as beams or ductwork, which are often present in attics.

Additionally, flex bits can reach areas that are otherwise difficult to access with a standard drill bit. They often have a long reach, enabling the user to drill at an angle or into confined spots, which is essential when running wiring for a keypad installation.

In contrast, while wood bits, twist bits, and spade bits are effective for more straightforward drilling tasks into specific materials, they lack the flexibility needed for working in constrained attic spaces. These types of bits are generally suited for vertical drilling into flat surfaces, but they do not facilitate the kind of maneuverability that the installation in an attic requires.