In this note we discuss some aspects of the phenomenology of a light charged; Higgs ($M_{H^+} \lsim 150$ GeV),  allowed at low and moderate values; of $\tan \beta$, in the NMSSM and CPV-MSSM, respecting all the LEP-II bounds. In NMSSM with the $H^\pm$  near its lower mass limit; $(M_{H^+} \simeq 120 \ {\rm GeV})$, and a; light pseudoscalar $(M_{A^0_1} \simeq 50 \ {\rm GeV})$ with a very significant; doublet component, the charged Higgs boson  is expected to; decay dominantly via the standard $H^+ \rightarrow \tau^+ \nu$ mode.; One can probe this mass range via the $t \rightarrow bH^+; \rightarrow b \tau^+ \nu$ channel at Tevatron and especially at; LHC. For somewhat heavier charged Higgs boson $(M_{H^\pm} >; 130 \ {\rm GeV})$ the dominant decay via the $H^+ \rightarrow W^+ \; A^0_1$ channel provides a probe for not only a light $H^+$ but also a; light $A_1^0 $~\cite{Drees:1999sb} in the moderate $\tan\beta$ region,; where  its dominant decay mode is into a $b \bar b$ final state.; Similar situation also attains in the CP-violating MSSM as well.; The CP-violating MSSM allows existence of a light neutral Higgs boson ($M_{H_1}; \lsim 50$ GeV) in the CPX scenario in the low $\tan \beta (\lsim 5)$ region,; which could have escaped the LEP searches due to a strongly suppressed; $H_1 Z Z$  coupling. The light charged $H^+$ decays dominantly into the; $W H_1$ channel again giving rise to  a striking $t \bar t$ signal at the LHC,; where one of the top quarks decays into the $bb \bar b W$ channel, via; $t \to b H^\pm, H^\pm \to W H_1$ and $H_1 \to b \bar b$. The characteristic; correlation between the $b \bar b$, $b \bar b W$ and $b b \bar b W$ invariant; mass peaks helps reduce the SM background, drastically.