If you use an MS account you change the password through that. That password has nothing to do with your network though.
"CHALIE" is the host name being give to your router by one of the devices connected to it.
Do you have wifi? if so, change the password. You'd have to go to a particular URL to change that. most commonly it is 192.168.0.1 but it might be indicated on your router. A username and password login are needed for it which, too, should be indicated on the unit from when it was installed.
It is many times more likely that the "CHALIE" system is a device you've simply never considered. A smartphone, tablet, Smart TV, or even a cable box. You may have friends or relatives who visit and to whom you've given the password.