I have an issue with the mortice lock on the door of my flat that's in a communal building (3 other flats) - it locks and unlocks fine from the inside, and locks fine too from the outside. However, over the last few days, unlocking it from the outside is getting trickier - if it seems to be stuck, giving it a quicker turn with a bit more force behind the turn budges it. I've not been locking it just in case when I go out, which of course isn't ideal - is there anything straightforward I can try (WD40 etc.)? I am one of the least DIY minded people ever so anything involving drilling or taking the lock out is beyond me!
