I have lost the medium speed on my ceiling fan, now only have low and
High.
Can I get the medium speed back?

Were you controlling the speed with a remote, a wall switch or the pull chains?

Were you controling the speed with a remote, a wall switch or the pull chains?

I was controlling the speed with a pull chain

Disassemble the fan, remove the switch and replace it with another 3 speed switch. Note that not every manufacturer uses the same colors so you may be figuring it out by trial.

Disassemble the fan, remove the switch and replace it with another 3 speed switch. Note that not every manufacturer uses the same colors so you may be figuring it out by trial.

Could I just take the switch out, look at the colors, and order a 3 speed switch
That has those colors?

Yes you can, especially of you know the brand and model

Take a picture of the switch and go to HD, Lowe's or an electrical supply house and see if the colors match up. Typically there will be 4 wires, 1 hot (usually black) and 3 for the speeds. The one I have in my electrical box is red, yellow, purple and black.