I was trying to replace a ceiling fan 3 speed switch. I forgot to mark the wires. I have a red wire coming out of forward and reverse. I have a black wire coming out of the ceiling and I have a blue and black wire coming from the motor of the ceiling fan. The switch is marked L, 1, 2, 3-Do you know what wires go where?

They go in the same places they did on the old switch. Usually black is L.

It sounds like you only have 3 wires? Your replacement switch requires four.

Check this page:

http://www.ceiling-fans-n-more.com/ceiling-fan-pullchain-replacement-and-repair.php