what i did to my Cabinet to light prof it i took a stack of paper and cute it into strips about to what ever thickness needed then rap it in electrical tape then glue it on so when the door closes it seals the light
That cheap black foam weather stripping works well. It comes in different widths and thicknesses and comes on a roll. It is adhesive and sticks nice. It will create a pretty tight seal on there. It only costs around $5.00 a roll and would doo your whole cabinet.
This box is just under 2 1/2 feet tall my plan is when they get halfway to the lights i'm gonna start to flower them as long as theirs enough nodes.