Optical and electrical measurements on vapor co-deposited thin films of the most conducting electride, K+ (cryptand[2.2.2])e(-), show results similar to those obtained with polycrystalline pellets and with thin films prepared by solvent evaporation. Initial optical absorbance spectra of films deposited below -50 degrees C showed contributions from several species, but these spectra evolved with time (annealed) at low temperatures to yield mostly plasmalike spectra, characteristic of marginal metals. Most films deposited at -40 degrees C showed no change in shape with time, indicating that annealing had occurred during deposition. Four-probe conductivity measurements showed activated temperature dependence with an activation energy of about 0.03 eV, while two-probe conductivity measurements showed similar activation energies, but with a variable resistive barrier at the sample-electrode interfaces. The correlation between conductivities and the decay of the absorbance spectra during decomposition was investigated. Thermal decomposition of the electride films leads to complex conductivity behavior. Except when the temperature is increased very slowly, the films become more conducting during the first 40-50% of decomposition, and then the films rapidly become insulating. The conductivity may be, due to defect holes that can disappear by annealing or slow decomposition or can be produced during the early stages of rapid decomposition. Alternatively, variable grain-boundary resistance could be responsible. The optical and electrical behavior of the films is correlated with the cavity-channel geometry of this electride.