Why can you never catch a 'ghost' particle in a detector?

Ghost fields appear in several theories of gravity and quantum field theory, but they carry negative probability, threatening physical consistency. This work shows that a ghost particle's dressed propagator develops complex-conjugate poles that cause it to become quantum-mechanically indistinguishable from ordinary multi-particle states at late times—essentially dissolving into the background before any detector could register it. The timescale for this camouflage is set by the inverse of the imaginary part of the ghost's complex mass, confining any ghost-like behavior to very short intervals.