Contact your local police (not 911, call their desk or offices or whatever), and let them know about your brother and that the next time he comes over that you'll signal for them to come over and take em away.
Next time he asks for a bath/shower/food, whatever it is that allows him into your house, let him, seriously, let him walk right in and do whatever. But as soon as he enters and starts doing whatever, call 911 letting them know he's there (if you don't contact them prior to it could be a way longer phone call that your brother might hear, so alert them prior to that you'll be calling in so they know right away what you're talking about), and then they come and arrest him. Simple as that.
what an awful idea. they won't be able to do anything. you will not be arrested just because your grandparents think you stole something. and if you still
let him into your house they will do even less than nothing, i.e. probably ignore your accusations against your brother in the future
do not let your brother into your house. if he decides to break into your house later then you should call the cops, and you may actually be able to prove it then
