I am re-wiring my well house. The previous owner had run 12/2 wire (no
ground wire) from a 100 amp breaker on the service panel to a 30 amp
breaker in the yard on a metal stake, then on to the pump house. Along
this run were 2 splices covered with electrical tape. At the well
house he then ran a wire off one leg of the pressure switch and one
wire off the well casing to run a light bulb and heat tape. It looked
like an accident waiting to happen.

The pump motor is: 3450rpm, 3/4HP; Franklin Electric Motor, model
#2445070117, 3/4HP, 1ohm, 230V, 3450rmp, 6.0amp, 2 wire
I plan to use a 60 watt bulb for freeze protection.
The distance to the well from the service entrance is ~65 feet. I plan
to use 12/2 w/gound in conduit (I already have this wire and want to
avoid buying more wire)

Questions:
1. Will a two pole 20amp breaker be sufficient at the service
entrance?
2. If I pull a single 12 gauge wire to the well house, along with the
12/2, can I wire in a 110 circuit for a light?
3. How do I wire the circuit at the well house. Do I need a sub-panel
at the well house with a 20 amp, two pole breaker and a single pole 15
amp breaker?

Wiring to the pump seems straightforward but wiring for a simple light
bulb seems to be adding quite a bit of cost.