Circumnuclear regions provide a key environment for studying how old stellar populations, supermassive black holes, and the multiphase interstellar medium interact. We use multi-wavelength, high-resolution observations of nearby LINER-like systems, including M31, M81, and early-type galaxies (ETGs) such as NGC 524, NGC 1387, and NGC 4710 to examine the origin of their ionized gas emission. We construct CLOUDY photoionization models using stellar radiation fields, gas-density constraints, and observed galaxy structure, and compare the predicted emission-line profiles with IFU observations. The models suggest that evolved stellar populations can provide an important ionizing baseline, but may not fully reproduce all observed lines simultaneously. In particular, [S II] and [O III] show possible tensions with single-phase photoionization models. The ETG sample offer an additional test of this picture. Preliminary comparisons indicate that multiphase gas structure, disk-interface emission, turbulent mixing, or shocks may contribute to LINER-like emission in some systems. These results motivate a broader investigation of how photoionization and mechanical processes jointly shape circum