Can any one direct me to a diy lightrap?

just like it says. i looked in the grow faq but that's not the style i'd like. anyone help out?

i just built this one ....... https://www.rollitup.org/indoor-growing/72532-intake-vent-light-trap.html

i looked at yours in another thread- i like it, but it won't work for my setup. i need one to be inside my cab. i have a mother area/ daughter area separated equally. the mom room is on top (like a tall locker). then i have a flower area that is four times the size of the mom and daughter room separated by a wood wall. the mom room vents to the flower room from the top. i need a light trap for this. i have a 6 in hole with a desk fan to push the air from mom to flower room. how do i make a light trap?