I've used the Megascan Abandoned Apartment scene, I removed all the lighting and made my lighting form scratch.
I intended to bring a warm atmosphere to the world.
Base scene:
I've added and adjusted:
DirectionalLight / ExponentialHeightFog / HDRI Backdrop / PostProcessVolume / SkyAtmosphere / SkyLight / VolumetricCloud
I've worked on the light color, intensity, light shafts, volumetric fog, exposure, lens flares, and depth of field, and reworked the particles of dust.
I've added a billboard Lensflare fx material over the light buld to bring more subtile details on the lighting, halo, star, glow, flares fx.
The flickering light effect is controlled by a material function on the light and a material shader on the bulb mesh.