light leaks from air intake /air flaps of homebox ?

[charlesweedmore]

hi folks

i use only 1 fan as extractor ,i use passive air intake /air flaps of homebox for intake ( negative pressure )

but there are many light leaKS from air flaps to inside of homebox.
how can i use air flaps of homebox ?
or must i use an activa intake ?

thanks .