Thank you Volvo, I always appreciate the help.
The cap to my cistern (large plastic holding tank) looks like what you see here.
From what I can tell there are two ways to install the float switch.
The first way is from the side of the tank dangling down. To do this I guess some kind of tank wall sealing pass through is used or the tank would leak there when full. Which for me will be most of the year. (Note these are NOT images of MY tank.)
SIDE MOUNT
The other way seems to be from the top... down on a PVC pipe. As seen here. This was what I was going to originally do unless someone has a better idea???
TOP MOUNT looking down into a tank.
The blue float switch is mounted on the pipe, toward the bottom, as seen here.
To mount the PVC pipe inside my tank without opening it up to outside critters I was going to drill a 1 inch hole in the cap, thread a PVC coupling on each side then glue the PVC pipe, to the coupling and allow for a way to thread my wires through the cap.
This solutions would allow me to remove the whole kit and kaboodle for when it needs servicing.
Does anyone else have a better suggestion? I have been known to over engineer ideas in the past.
Thank you everyone!