Lightning Web Components : Use LWC in Aura Components | Handle LWC Event in Aura Components #LWC

have you got any solution on the event handler in aura component?

Hey, do you have an example of firing an event from Aura to LWC using auraPubsub module? I am not finding anything with respect to that anywhere ..not even in developer guide

You should use like the below code for fetching data passed from LWC event:
LWC::
const testmsg= 'I am in next loop';
const nextEvent = new CustomEvent('next',{detail:{testmsg}});

Aura controller::
var details = event.getParam('testmsg');

The event param should not be const message variable name, it should be "detail", as you are passing message to detail as a event param.