I have a well that runs on 220, I want to install a 110 out let in the well house. And maybe a 110 light how do I do it, thanks; Larry

Your well is most likely a 3 wire system, 2 hots and a ground. 120V needs a neutral. You will need to run a separate feed to the well house. If there is a separate disconnect in the well house, open it up and count the wires.

You could run 4 conductors from the house, and have a sub panel, you can get your 120 and 240 volts and still not be obsolete.
Maybe 2 #6's, an 8, and a 10 for a little 60 amp subpanel? I not a great distance, and you could use 3/4" PVC Conduit.

You can get a small transformer, 240 volt to 120 volt, say 2000 VA, put at the well end, have it feed a 2 circuit panel at the well.

This will eliminate the need of running any new wire.

TK. I thought that they wanted to keep the 240 and split off a 120. If they only have 3(which we are not sure of) wires and keep the 240, where does the neutral come from for the 120?

One leg of the 120 volt output of the transformer needs to be grounded.

MA0641, are you an electrician?

TK. No.I have done a lot of Habitat for Humanity wiring under an electrician and have wired 2 houses of my own. On the transformer issue, the ground acts as a neutral? I have done 120 to 12V and 24V, not 240 down. That's why I asked THX, Brian

The ground and Neutral are at the same potential, zero volts between the 2, but need to be separate, the neutral carries current, the ground carries current if there is a fault.