To do this cheat you need the following (on Secret Builders) :-
1.Sweater Vest
2.10-20 puffs
How to do-
First put the puffs. Then go to Wardrobe and put on your Sweater Vest. After doing this, you need to sit and get up quickly on one of the puffs. Now you are invisible and people can only see your name and a two dots of Sweater Vest.