As long as the cash was legally gotten then you're allow to keep as much cash stashed away at home as you want too.
It's not illegal to have large amounts of cash but it's better to keep most of your cash in the bank because if someone robs your home then you could lose the money or if your house caught fire the cash could be burnt up.
Also if you put your cash money into a savings account then the money will grow into more money but it won't do that at home.