There are a number of them readly avalable on the internet.

Google - jQuery-Mask-Plugin-master

I personally use the CDN mostly nowadays (NOTE: only option when using Laserfiche cloud) much easier IMO.

Below is the javascipt for Phone & SSN Masking using the CDN, just assign phone or ssn under class on the field.

$(document).ready(function () {
    $(".ssn").on("focus" , "input" , mask_num1);
       function mask_num1(){
           $.getScript('https://cdnjs.cloudflare.com/ajax/libs/jquery.mask/1.14.16/jquery.mask.min.js', function () {
                  $(".ssn input").mask("999-99-9999");   
           });
       }
       $(".phone").on("focus" , "input" , mask_num2);
       function mask_num2(){
           $.getScript('https://cdnjs.cloudflare.com/ajax/libs/jquery.mask/1.14.16/jquery.mask.min.js', function () {
                $(".phone input").mask("(999)999-9999");  
       
           })
        }
    });

Below is what it looks like once implemented, it will automatically insert the -'s and ()'s in the Phone Number and SSN fields as long as you assign the class and insert the script above into the Javascript section on the form.