Yes, there is a general principle that all resident should have access to common property. There is also a general principle that law should be interpreted in a reasonable common sense manner.
So, for reasons of safety and avoiding mischief, it is not a good idea to leave the switchboard open for all to access and that would not be in conflict with a reasonable interpretation of the law. For another example, nobody can occupy exactly the same bit of common property as is being occupied at that moment by another resident, or is being occupied by a tree for that matter, but nobody applies excessive pedantry to those situations!