  Numerical simulations were used to study signal formation in a Thick Gaseous
Electron Multiplier (THGEM) and in THGEM -based Thick-WELL (THWELL) and
Resistive-Plate WELL (RPWELL) detectors. The signal shapes were simulated in
mixtures of Argon and Neon with $5\%$ Methane under irradiation with soft
x-rays and muons. Anode-induced raw signals were convoluted with the response
functions of charge-sensitive and current-sensitive pre-amplifiers. The
simulation toolkit was validated by the good agreement reached between the
simulated and measured response, with different pre-amplifiers. It indicates
that our simulations framework provides valid insight into the inherent complex
dynamical processes of the various detectors.
