Window AC, Light leak problem....

So, I built a new 4x8 flower room in a spare bedroom around a 12k BTU Window A/C unit.. I will be running 1k HPS, 1k MH & adding a 600w HPS if the AC cools as needed. My problem is the A/C unit is letting a wee bit of light in around the bottom left of the internal cabinet.. The light is actually coming from inside the A/C unit, not around where she sits in the widow.. Would it be ok 2 wad up sum insulation from outside & try and stuff the light leak shut?? Or would this be a fire hazard??

Any other ideas on how to counter the problem? I've been smokin & brain storming all day & still nuffin has came to mind

Thanks in advance!