  Experiments searching for parity- and time-reversal-invariance-violating
effects that rely on measuring magnetization of a condensed-matter sample
induced by application of an electric field are considered. A limit on
statistical sensitivity arises due to random fluctuations of the spins in the
sample. The scaling of this limit with the number of spins and their relaxation
time is derived. Application to an experiment searching for nuclear Schiff
moment in a ferroelectric is discussed.
