Hacking at MIT
I can't vouch for the 1950s, but by the 60s when I was at MIT, a "hack" (N) and "hacking around" (V) both referred to ingenious and relatively harmless tricks, always involving technology, which occupied our "idle" time. NOTE: We didn't really have time to have idle time, so hacking was in lieu of the many "important" things we were supposed to be doing, effectively avoiding real work; but since it had a technical design and implementation character, we could justify it as being as educationally useful as the real work.