The truth is, a good old fashioned flyer that they can hold on to will be wildly effective for inviting people.  Then give an email or facebook reminder a few days before the event!

Set up a stage area with multicolored bulb clamp lights and a microphone.

Make felt costumes for old trophy statuettes to theme a silly award or prize. 

Eg: Most Beautiful - feather boa and tutu on a cheerleading trophy
      Most Scary - use a bowling trophy to make the headless horseman costume.
      Most Original - Any crazy mad scientist costume will work.

Having an acceptional participation game will give people an activity to focus on instead of gossiping and dividing into cliques or standing around waiting for something to happen.

WE WILL DO IT ALL FOR YOU! If you want to be part of the fun without all the hosting work,  Hire Heather to play it straight or have one of her many characters MC your party.

Be over the top in your MC of the event with fictional introductions for the judges and allow acceptance speeches for the silly trophies.

The shy nonparticipaters will have a blast watching and laughing and may inspire their interest for next year!

Keep it silly so no one is working too hard to impress!

Have a Show or Contest For your guests to plan and look forward to

 Appoint judges and give them number cards to hold up or model any of your favorite game show judge methods.  

(Be careful of a gong show type so no one gets their feelings hurt) 

Choose a judge from each demographic such as work friend, family member, and neighbor so that the whole crowd is mixed up and entertained.