"Ursäkta, god natt!"
Translation:I am sorry, good night!
This sounds like it's missing a few word in the middle. Wouldnt you say "Excuse me, I am going to bed, good night!"? If you where at dinner and just stod up while saying "Excuse me, good night" and left the room it would be quite weird. Same in swedish, if you stand up and say "ursäkta, god natt" it would be very abrupt and quite antisocial. You would need to say "ursäkta, nu går jag och lägger mig, god natt!" to make it make sense in a social context.
If you are encountering someone on the street at a late hour that you just REALLY don't want to talk to (right now or in general), you can try and cut the conversation short by something like "I have to go. Excuse me, good night." Then again, by far not all phrases on here make sense.