The electronics or decryption skills are passive apart from the abilities you unlock when leveling them up. when it comes to interacting with consoles/lockers in the environment you can't task your squad to do it for you.
I play as a Soldier who has neither skill and with my squad i always have Tali and Gerus, both have Electronics and Decryption skills which i normally focus on one from each of them and i am still able to unlock/open almost anything, so it appears that consoles/lockers in the game which require these skills are based off from the party's skill (unsure if it's the highest value or the party's total value) when you interact with them
Evidence to this is in the Eden Prime Mission when playing as a Solider, unless you spend points on Kaiden who is the only one in the party who has both skills (if you are a Soldier), you'll be unable to open the door after the first encounter with Husks where you find those scientists (one female who praises "the maker" that your humans (which seems like a Dragon Age reference) and one male who speaks of "a Turian" (Seran) as a Prophet of Destruction, a Dialog Option has you knock him out) or the lockers by the beacon.
When you approach an object which requires one of these skills you are given the object's name and underneath (on 360) you will either have the A button appearing and next to it Easy/Average/Hard Electronics/Decryption if your skill is high enough or you have "Skill too low" if it's not