  We propose a novel method for measuring the charge radii of charged stable
hadrons, with which the first measurement of the charge radii of the $\Sigma^+$
and the $\Xi^-$ is foreseen. The method explores the facts that the Dalitz
decay $\psi(2S) \to Y\bar{Y}e^+e^-$ contains the hyperon form factors and the
lowest measurable four-momentum transfer squared can be as low as $\sim 4m_e^2=
1.05\times10^{-6}\,{\rm GeV^2}$ in the time-like region. We identify a
kinematic region where the hyperon form factors are essential and propose a
method for subtracting the background from the data. It is estimated that the
hyperon charge radii can be measured to a precision of about {0.2~fm} with the
BES\Rom{3} experiment and one order of magnitude better at the future Super
$\tau$-Charm Facility. Moreover, the same method can be used to measure the
charge radius of the proton, which provides an independent cross-check on the
extraction of proton radius from elastic $ep$ scattering or leptonic hydrogen
spectroscopy.
