  Ghost vortices constitute an elusive class of topological excitations in
quantum fluids since the relevant phase singularities fall within regions where
the superfluid density is almost zero. Here we present a platform that allows
for the controlled generation and observation of such vortices. Upon rotating
an imbalanced mixture of two-component Bose-Einstein condensates (BECs), one
can obtain necklaces of real vortices in the majority component whose cores get
filled by particles from the minority one. The wavefunction describing the
state of the latter is shown to harbour a number of ghost vortices which are
crucial to support the overall dynamics of the mixture. Their arrangement
typically mirrors that of their real counterpart, hence resulting in a ``dual"
ghost-vortex necklace, whose properties are thoroughly investigated in the
present paper. We also present a viable experimental protocol for the direct
observation of ghost vortices in a ${}^{23}\mathrm{Na}$ $+$ ${}^{39}\mathrm{K}$
ultracold mixture. Quenching the inter-component scattering length, some atoms
are expelled from the vortex cores and, while diffusing, swirl around
unpopulated phase singularities, thus turning them directly observable.
