very possible the ladder’s UVs are bad.
Did you make the light-map yourself or was it engine generated?
And it seems like the last block above the ladder is a separate mesh that’s got some light bleed to it. Hard to say without actually looking at it, but I would guess that’s the reason why it’s lighting beyond the wall maybe?
Start with the UV first.
Check the model after - make sure they intersect or are at exact zeroed-out coordinates.