not as risky as you think i put 3 screws in box and used white paint to determine location of holes by placing board in case on screw heads so paint would leave a mark on back of board
then i checked for trace interferance before i drilled any holes,
after that i made a templete the same size as a board with the holes drilled in it
i use it to predrill boards before assemble of le
i did this to preserve water tight integrity of box as we get a lot of rain in central mississippi during nov. and dec