nodejs: Cannot interact with data from websocket using eventEmitter

Question

this is my first so be gentle.

I am streaming data from a site using this:

"use strict";
const ws = require('ws')
const w = new ws('wss://website')

w.on('message', (msg) => console.log(msg))

let msg = JSON.stringify({

     ///STUFF
})

w.on('open', () => w.send(msg))

And I would like to create an event listener that responds to the data from the websocket stream.

///confused about how I define what price target is!? 
///I would like it to set an event trigger on particular value from 
/// websocket data

var ticker = require('./openTick');

///not sure if I can check the msg like this
ticker.emit.on('priceTarget', function(){
    if (msg == priceTraget) {
        /// Run fracMarty.py
    };
});

Write now the "msg" is being displayed on the screen but I can not interact with it i.e.) iterate over it etc.

I have tried the eventEmitter modules on tut, the nodejs site, and like 4 others and they all direct me to just get the connection not interact with the data.

Can someone point me in the right direction.

Thanks, Bobby Fischer