Hampton bay 3 speed fan pull chain broke inside the switch. How do I go about replacing the switch when I do not have a wiring schematic?

Home depot or should have replacement.
The color of the wires are important,
Go to the first sticky under "Electrical and Lighting" lot of good info, answer probably
There.

See:

Ceiling fan pull chain replacement and repair - Ceiling Fans N More (http://www.ceiling-fans-n-more.com/ceiling-fan-pullchain-replacement-and-repair.php)