Well, in the internet you can find a lot of pages and blogs that talk about how to play in bubble. And what is the bubble? Is the point on a tournament where the next player eliminated will leave with empty hands and all others players will cash in some money.
Well, I play the bubble very aggressive (all in almost all hands) at this stage of the tournament, no matter if I have a few chips (10BB) or a lot (chipleader).
Because if I have a few chips the blinds will eat me and I will be the Bubble Boy without seeing any action. Otherwise, to have a lot of chips give me a greater presence on the table and many will fold with hands that may be they were played in another situation by their fear of leaving empty-handed.
This way you steal the blinds, which for the time of the bubble are high.