  A general two Higgs doublet model (2HDM) is adopted to study the signature of
flavor changing neutral Higgs (FCNH) decay $\phi^0 \to t\bar{c}+\bar{t}c$,
where $\phi^0$ could be a CP-even scalar ($H^0$) or a CP-odd pseudoscalar
($A^0$). Measurement of the light 125 GeV neutral Higgs boson ($h^0$) couplings
at the Large Hadron Collider (LHC) favor the decoupling limit or the alignment
limit of a 2HDM, in which gauge boson and diagonal fermion couplings of $h^0$
approach Standard Model values. In such limit, FCNH couplings of $h^0$ are
naturally suppressed by a small mixing parameter $\cos(\beta-\alpha)$, while
the off-diagonal couplings of heavier neutral scalars $\phi^0$ are sustained by
$\sin(\beta-\alpha) \sim 1$. We study physics background from dominant
processes with realistic acceptance cuts and tagging efficiencies. Promising
results are found for the LHC running at 13 or 14 TeV collision energies.
