Light Leaking Problem [Begginer]

Geometry is Closed Completely,
But Light Leaks from somewhere

How Can I solve in this Case?
What Parameter should I Change?

Please let me know

Your floor is extending beyond the walls, light will illuminate the surface on the outside and the illuminated pixels will be slightly visible on the inside since the pixels will not line up with where the wall is. When that happens, the bleed will make things worse inside since it will add even more illumination.

Also, make sure that for walls you have an outer wall and the wall has thickness, the outer wall will block lighting.

Also, make sure your lightmap resolution for your meshes are high enough—lower resolution means that the pixels will be larger, if the pixels are large then they can more easily bleed over.