But it's a good idea to stop the supply in nights . Many have the habit of leaving the mobile and If suppose some short circuit occurs , then it ll be a big disaster , since Rexine catches fire . At least in day people will some time to react but night is a problematic one as many will be sleeping
OC relays are there for the exact same purpose, they'll shut the supply off and disconnect the faulty part of circuit. However, that may not work if the charger itself is of poor quality, or the mobile has components of poor quality. the ideal response here is to use fire retardant materials and paints, but that ain't happening.