Hearing things that go bump in the night

I'm currently battling acute bronchitis so I have been virtually robbed of sleep the last few days and I'm up at all hours coughing my lungs out.

On each of these last nights, at around 2-4am (give or take), I have heard two banging noises ocurring somewhere in the house that sound like a cupboard or cabinet being closed.

Firstly, I live alone so no-one could be opening cupboards at 3am. Secondly, the noises don't sound like any cabinets I own.

So what on earth could be causing it? An intruder? Unlikely. Nothing is missing and there are no sounds of anyone moving through the house. A ghost? I don't believe in them, and I haven't felt any "presence" nor seen any other supernatural phenomena.

I'm not scared necessarily, but I wish I knew what was causing these bumps in the night.

PS: Remember the children's show Bump in the Night? i used to watch reruns every afternoon after school. Absolute kino.