  We calculate the complete form of the dimension-8 condensate contributions in
the two-point correlator of the ($1^{-+}$,$0^{++}$) light hybrid current
considering the operator mixing under renormalization. We find the inclusion
these higher power corrections as well as the update of $\langle g^3G^3\rangle$
increase the QCD sum rule mass prediction for the $1^{-+}$ light hybrid. The
obtained conservative mass range 1.72--2.60 GeV does not favor the
$\pi_1(1400)$ and the $\pi_1(1600)$ to be pure hybrid states and suggests the
$\pi_1(2015)$ observed by E852 is more likely to have much of a hybrid
constituent. We also study the $b_1\pi$ and $\rho\pi$ decay patterns of the
$1^{-+}$ light hybrid with light-cone QCD sum rules. We obtain a relatively
large partial decay width of the $b_1\pi$ mode, which is consistent with the
predictions from the flux tube models and lattice QCD. More interestingly,
using the tensor interpolating current we find the partial decay width of the
$\rho\pi$ mode is small due to the absence of the leading twist contribution in
the light-cone expansion of the correlation function.
