How to get JSON object values with the JSON keys having spaces in Node.js

ONE POSSIBLE CASE: when you again do JSON.stringify() on a string value this could happen. That's why it throws values as undefined, so don't use unnecessary JSON.stringify() here

var response = "response"
JSON.stringify(response)
""response"" 
^^        ^^ see extra quotes here   

var result = { "source": "agent", "resolvedQuery": "LPTP-KDUSHYANT", "speech": "", "action": "gethostname", "actionIncomplete": false, "parameters": { "solution": "Profile Issue", "hostname": "LPTP-KDUSHYANT" }}
var eventID = result.parameters.solution;
var EVENT_ID = {
  "Enable Popup Blocker": "Sol_EnablePopupBlocker_IE",
  "Disable Script Debug": "Sol_DisableScriptDebugger_IE",
  "Clear History": "Sol_ClearHistory_IE",
  "Reset Settings": "Reset_InternetExplorer_Settings_SA",
  "Profile Issue": "Fix_Outlook_Profile_SA",
  "Send Receive": "Fix_Send_Receive_Errors_Outlook_SA",
  "Search Issue": "Fix_Search_Outlook_SA"
};

var aptEventName = EVENT_ID[eventID];
console.log(aptEventName)

JSON.stringify called on a string will return the string in quotes. You should not JSON-encode your key. And as string typecast is implicit when performing object field access you can type it just as:

var eventID = req.body.result.parameters.solution;
var aptEventName = EVENT_ID[eventID];

You should not be using stringify, it is taking a string and turning that string into JSON.

var eventID =  JSON.stringify(req.body.result.parameters.solution); 

when you do this your string is going to be

var eventID = "\"Profile Issue\"";

So of course you have no properties in your object with quotes. So what you need to do is drop the stringify bit and just have to reference the property in your object.

var eventID = req.body.result.parameters.solution;
var aptEventName = EVENT_ID[eventID];

You can get the values using:

EVENT_ID["Clear History"]

I think you have something wroong with the req.body.result.parameters.solution.