**Random** selection of a member's location in a nested cell of cells: Matlab

I have a nested cell of cells like the one below:

CellArray={1,1,1,{1,1,1,{1,1,{1,{1 1 1 1 1 1 1 1}, 1,1},1,1},1,1,1},1,1,1,{1,1,1,1}};

I need to randomly pick a location in CellArray. All members' locations of CellArray must have same chances to be chosen in the random selection process.