If you are at a half-way house through a voluntary program, then you just run the risk of being kicked out of the program. However, most half-way houses are not voluntary programs and, instead, are run by probation or parole.  If your stay at the half-way house was part of a program that you were required to comply with, then you run the risk of being violated on your probation or parole.  Get with your parole office and arrange your return.  Failure to do so could result in a warrant being issued for your return.