Intruder Or Ghost?

This is my first time posting so I apologise if I haven't explained myself clearly.

This strange occurrence happened back in July 2011. Me and my partner at the time were babysitting my partner's nephew at his sister's house. It was a normal summer's evening. We had all been out in the garden playing until nightfall. His sister was out at the time so it was me, my partner and my partner's nephew.

Shortly after putting my partner's nephew to bed, we put the TV on and I distinctly remember watching a program about lottery winners. We were sitting there blissfully when all of a sudden we heard the kitchen door at the back of the house slam shut. I had shut it when we came in from the garden. We both sat there wondering why it had slammed shut as the bang was so loud, when all of the sudden we heard a noise as though someone was going through the knife draw rattling the cutlery.

Instinctively we both thought an intruder was in the kitchen to steal some valuables. We were both as quiet as possible so we didn't startle the 'intruder'. I stood at the bottom of the stairs ready to run up and protect my partner's nephew if necessary and my partner stood by the kitchen door. It was so frightening the prospect of someone being behind that door with a knife and perhaps not knowing we were there.

I insisted we call the police but my partner decided to pick up a vase and enter the kitchen to confront whoever it was. To our surprise, nobody was in the kitchen and nothing was touched. Both of our phones were on charge in the kitchen next to the knife draw and they were still there. Also we didn't hear the back door shut again.

I am positive it wasn't an intruder as nothing was touched and I am sure they would have taken the phones as they would have been quick to grab and scarper with. The house is also detached so I highly doubt it was noise coming from a neighbor.

The only thing I can think of is perhaps a ghost or entity? I have had a similar experience in the same kitchen where I heard somebody sneeze behind me and I was the only person in the house at the time. This happened a few weeks before the above event.

Please feel free to let me know your thoughts, but this was definitely the most frightening experience of my life.

Best wishes.

Lion_tamer