Wild LI geezer built basement shooting range and staggering gun lab — just steps from Chaminade High School: DA

Police uncovered 10 mostly illegal guns, including seven assault-style rifles, a home-assembled fully automatic MP5-style weapon, a 9mm ghost gun with illegal parts, 78 high-capacity magazines — some stashed in Chou's ceiling — along with six suppressors, roughly 6,000 rounds of ammo, and a…