In this study, two geometries of Thick Gas Electron Multipliers (TGEM) were employed for alpha particle detection in the Self-Quenching Streamer mode (SQS mode). This mode was followed by the appearance of streamers in the range of the visible light spectrum. The streamer intensities were measured by an Ambient Light Sensor (ALS) and these streamers appeared with intensities around the same illuminance at different input voltages. After the appearance of the primary streamers, an increment observed in the streamer intensities versus the voltage difference between TGEM electrodes. There is demonstrated that in the presence of the sources with different activity and a TGEM with the high accuracy in the geometry, the detector entered to the SQS mode in the different applied input voltages.