Ok so there is this thing under the steering wheel, connected to the collum that always falls off in my lap, what is it and why does it happen how do i fix it? thanks!

 

do you mean the plastic part? just around the stearing coloum just after the stearing wheel?...if thats the part someone might of took the screws out and forgot to put them back in, in the bottom of it holding it to the top plastic piece