Offenders who, at the time of sentencing, meet the guidelines for a conditional sentence are permitted to serve their 'incarceration' time in the community and living in their residence. Typically, a conditional sentence (commonly referred to as House Arrest) involves terms that the convicted person must remain in their residence except for specific circumstances.
There is no electronic monitoring, so if the person who promises the court to obey the order, fails to obey the rules, and are caught... they will be arrested and appear before a Justice where a hearing will determine whether they should forfeit the privilege of serving the remaining time in the community at home or go to jail for the remainder of their sentence.
A conditional sentence may include exceptions for a few hours on one day of the week to shop and attend to personal matters. It also may allow for the offender to be out of their residence for medical, education, employment or any number of other conditions which are clearly structured.
This lenient form of incarceration is not typically available to those who do not obey their conditions and cannot be trusted to follow the court order, and are rarely given more than once in someone's criminal career.
If this sounds like jail on the 'honour system'... it is. The police don't, as a rule, supervise these convicted persons. They are supervised by a probation / parole officer. If a police officer comes across or is informed about a breach of a conditional sentence, they will act.
However, this is still the honour system and relies on the offender keeping their promise to the court, the supervisors keeping tabs on the offenders and the public to report (to police or the probation office) any person whom they suspect of being in breach of their conditional sentence order.