breaker and light swtich question

HI i have a question about my breaker i have a breaker in my box like the one in the pictures this breaker is a bd1515 or br1515 a 2 pole unit breaker is this like a 2 in one or are they actually 2 breakers on a single bus?


on mine one is for receptacles and other for lights what if the one breaker for lights gets too hot or a light switch has a arcing sizzling sound? would it effect the receptacle side of the breaker? could it damage the breaker or fry anything that is plugged into the power outlets on the receptacle side?






my teen kid held the light switch in the bathroom half way between on and off and you can hear a sizzling sound from arcing he says it sounded cool and i told him he wont think its cool when you have a fire! will this effect the breaker? the switch is a self contained like this one in picture it just has one set of copper wires (meaning just one single set of copper) going to it! some of these has 2 or 3 sets of wires going to them! it is in the bathroom the switch is right next to exhaust fan the exhaust fan switch is the exact same and that has 2 sets of wires going to it one in bottm and one at the top the bathroom is right next to the back bed room where breaker box is!

this is a mobile home light switch will the sizzling sound in the switch mess up the breaker or interfere or fry anything on the other side that has receptacles/outlets on it? maybe the switch? no breakers has tripped! does the breaker actually have 2 separate breakers built inside of it or is it just like one 30 amp breaker made with 2 switches to trip separately?



[/img]https://www.mobilehomerepair.com/wp-content/uploads/2017/03/5900-1.jpg[/img]