The reason the ladybirds are in your house in autumn is they are looking for somewhere to spend the winter. Ladybirds, as many insects do, will hibernate or "overwinter". Cluster flies and many other insects do this and shelter together sometimes in huge numbers.
In the spring time they will emerge from their overwintering location. Sometimes they end up accidentally coming inside, if they were for example spending the winter tucked away around a window frame. Older houses that have gaps around window frames are ideal places for ladybirds to make a winter home. They often gather in large groups so if you find one there may be more close by.
Lady birds won't cause any damage to your home, they won't eat clothing or carpets. Ladybirds feed on aphids, however during the winter the hibernating ladybirds survive from their fat reserves.
My advice would be just leave them, if you really want to get rid of them gently brush them of to a piece of paper and release them outside, no pesticide treatment is needed. To prevent further ingress in the future look to seal gaps around windows and doors. Do this during the summer months to prevent accidentally trapping hibernating bugs inside.