This scenario has happened to me probably no less than 10 times so far in my life. Never has anyone actually broke in, but at least I know how my reaction goes.
I am a light sleeper. I wake up to the loud noise, or the wife does. She starts freaking out. I grab my AK loaded with JSPs and hand it to her, then grab my pistol. Tell her to keep her phone near in case she hears anything else strange. Investigate the house with pistol ready.
I have a 5 month old daughter, so investigating noises is necessary whether they are malicious or not.
Before we had her, we lived in a couple much worse neighborhoods. That's when we had all the previous 10 or so incidents. My strategy then was to either clear only the upper floor of our living space and then wait to hear any more noises at the staircase, or just cover the doorway to our room and wait for noises.
I have had a scary false alarm before as well. Before I met my wife, I lived with my brother who also lived in a dodgy part of town. It was about 10pm and I was home alone. As usual, I had my .38 revolver by me just in case. I went to my room to go lay down and turned off all the lights. Just as I got to my room, I heard the door open to our apartment, but didn't hear keys.
I went to investigate the sound with my revolver at low ready and a flashlight. Turns out it was just my brother's girlfriend coming home.
She was a little bit startled but she understood.