prevent light from escaping grow cab????

i noticed that when i closed the closet doors and switched on the lights, bright light escapes from the sides of the doors. visitors can clearly see the escaping light. what should i do to prevent this? what to use and how to use it? i thought of those trash bags but it'll prevent a side of the growspace from reflecting light. what do you guys use? any pro techniques this amateur can use? the cheapest and easiest would be much preffered. thanks!

ps. extra question. IS IT ALLRIGHT TO PUT A THREE MONTH PURE SATIVA TO VEG when its 2.5 weeks flowering? it bloomed early cause i grew it outside while i was setting up. LSTed and foot+ long. what are the consequences?
thanks again.

cardboard & ducktape... get a cardboard box & cut it into 3 or 4 inch wide stripes ,, and as long as possible ,, so now u have a strip or cardbord 4 inches wide & 1 or 2 or even 3 feet long ,,,, tape them to the inside border of your door ,so the cardbord blocks light from the inside & no light escapes the door crqacks anymore , works great for me ,,, ~