How do you, or a character, act when you are afraid?

A sound wakes me. I don't move. I listen. And wait. Maybe it will happen again.
A few seconds tick by.
There it is. Tapping on something solid. Like thick glass, thicker than a window. The glass of the clothes washer. But why would there be tapping on the clothes washer?
I peel back the covers and slide out of bed. My husband sighs and rolls over as the movement tips the mattress to his side.
The cool air makes me shiver. I debate putting on the clothes that lie at the base of the bed, but that'll just take more time, and I'm curious about what's out there.
Tiptoeing across the hardwood floors barefoot, I try not to make a sound. My shallow breathing comes in and out. I squint and focus on the laundry door. It's cracked so I can't see all the way inside.
Should I approach from the hinges or the other side? My mental debate leads me to the opposite of the hinges. I stop and listen before peaking my head around the corner and flipping on the light. It's empty. The whole bathroom. Even the clothes washer.
I tap on the washer's glass viewing panel to see if the sound matches what I heard. It does. Exactly.
Confused, I glance around again. Did I miss something?
Not quite satisfied with my discovery, or non discovery, I go on a mission around the house, glancing out windows, checking doors. Everything is in order. Not a single thing out of place.
I decide to go back to the bedroom. There's no threat lurking, at least not one I can identify.
The sheets are cold, all my left over body heat evaporated. I snuggle in deep, curling up next to my husband. And listen.
Aside from my husband's even breaths, the house is silent. I say a quick prayer, and rest my head on the pillow, leaving our safety in the hands of the Lord.