House
A "house" is essentially a container -- for a person, a family, several families or even a large group with shared interests (think of the term "houses of worship.") In the Bible, a "house" is also a container, but for spiritual things rather than natural things. In various uses a "house" can represent part of the mind, the whole mind, a whole person or even a church. The other nuance to the word "house" is that it is generally used in regards to our affections and desires rather than our thoughts and principles. This makes sense; we tend to engage our thoughts and rationality when we are out in the world doing our work, but when we are inside our houses we are driven most by love for our families and the desire to be good to those we love. So "house" tends to represent the things we want and care about -- which are ultimately the things that define us.
Luke 11:24-26
24
The unclean spirit, when he has gone out of the man, passes through dry places, seeking rest, and finding none, he says, 'I will turn back to my house from which I came out.'
25
When he returns, he finds it swept and put in order.
26
Then he goes, and takes seven other spirits more evil than himself, and they enter in and dwell there. The last state of that man becomes worse than the first."