title: Regular Expression to replace non alpha characters with spaces
body: <p>I have been trying to build a regular expression but haven't been able to get one specific condition to work.</p>
  
  <p>I want a regex to remove all non alpha characters with the exception of dash (<code>-</code>). Dashes should only be replaced if they are prefixed by a space.</p>
  
  <p>I.e.</p>
  
  <pre><code>TEST-TEST -TEST#TEST.TEST
  </code></pre>
  
  <p>should be changed to</p>
  
  <pre><code>TEST-TEST TEST TEST TEST
  </code></pre>
  
  <p>I had been using <code>[^a-zA-Z0-9]</code> but haven't been able to include one OR condition init.</p>