  We discus the muonic decay of light charged Higgs boson for $m_{H^\pm}\le
m_t-m_b$ in the context of the generic two Higgs doublet model (2HDM) type-III.
We show that for both alignment limit scenarios, the $H^\pm\to\mu\nu$ signal
could be dominant and give alternative reachable signatures to those arising
from top quark production and decay.
