Every time I do a seminar, someone asks me where I buy my wooden eggs to use with the float and jig.
I buy them online in a place called Craftparts. Here is the LINK. I buy the 2 1/2 inch wooden "hen" eggs. You can buy these as unpainted or painted white. I buy mine already painted.
It's a homemade project from here. Drill the eggs out with a 1/8 inch drill bit. You might need an oversized bit to get through them. Run some plug wire through and put a loop on the end of the wire by twisting around a screwdriver. Clip off the excess. If you want, add a nail to the side of the float as a holder.
Some guys make this even easier by simply putting screw eyes in through the top and bottom. Note that the through wiring is much more durable.