1. If you tell a lie, you may get caught up in it and find that it comes home to roost.
2. Dorothy is convinced that she is ill and dying because her unhealthy lifestyle has come home to roost.

The expression probably originates from the idea of a bird leaving and then returning to its roost, the perch on which a bird rests. It is usually used to refer to something bad happening to someone who has demonstrated some bad behavior in the past.