We know there exists a non-measurable subset in [0,1). Call it P.

P is a non-measurable set constructed by identifying the interval [0,1)

with the unit circle in R^2. If I can find it online, I'll post a link.

Let A be a measurable subset of P. Show that A has (Lebesgue) measure 0.

I must admit I'm stuck as to how to proceed