Question:
Should I wire a 110v outlet from a 220v toggle switch or from an overhead light switch? I want to position the outlet just above the pool timer.

Background:
I would like to install a 110v outlet just above the pool timer. It will supply power to a wifi switch that powers on/off the pool. Though this switch is rated for 90-240vac I would like to go with a 110v outlet just in case I would like to plug something every now and then. I tested the WiFi switch using an extension cable, sourced from an outlet outside, 5 ft across from the pool house. Power sources to consider are a 220v toggle switch for the pool motor, an overhead light outlet, and another switch that for the outside pool house lighting.
There is also a 110v outlet outside across from the pool house. But I would have to meander wiring 4 ft away, 3ft left towards perimeter fence, then 15ft back into the pool house.

1-Of these which is more ideal to pull power from, if I don't have to mess with the outlet outside?
2-How do you tap into and wire from the source, where do you connect those wires into, on the new outlet?

 

Powers on/off the pool ?? Do you mean the 240v pump motor ?

Your picture doesn't show us anything really helpful.
What does that switch control ?
Pool wiring needs to be done very carefully to eliminate shocking issues.

 

First, there needs to be a neutral wire to get 120V from a 240V circuit. Second, the 240V circuit cannot be larger than 20A to have it also supply a 120V outlet.

 

The pool needs the 240v as is I think. So I think it's on to look somewhere else as a source. Can I use the light switch as a source for 110V receptacle? Will the breaker for the light switch be an issue if a receptacle is on the same power line?

 

You could get a 120/240 volt transformer, but that would likely not be very cost effective.

 

I thought of the voltage transformer method but didn't pursue it because I already have the supplies for the below method. Besides, I will still need a socket for it.

The pic is a toggle switch that cuts the 240v power to the intermatic timer for the pool motor.

I was told I cannot use either of the toggle switch lines as a neutral & ground are needed in the new receptacle. That the easiest way is to install a receptacle at the light switch by the door. Then just use a long extension wire to plug in the wifi switch.