My mother never gave us money to put in the box...we were "too poor." No widow's mite from our family.
The accounts servant normally collects the money after every meeting with another brother standing by to make sure he doesn't pocket any but this brother didn't see the checks or know the exact amount, The accounts servant counts it out and makes a slip for each box (ususally 3, worldwide, congregation, KH building), and a copy goes to the brother that was him who gives it to the PO. The only way he knows who gives is 1) by the checks 2) when $250 or more is given (cash or check) in the US a special form has to be filled out for the IRS 3) he sees what people put in...which is pretty darn hard to count from a distance 4) the person tells him.
If you never go near the contribution box and you are being watched, the safe conclusion might be that you never donate. But you could have given your share to someone else to put in for you...
I heard of a congregation that was several months behind in the mortgage payments to the WTS. After the accounts report was read to the congregation, a short talk meant to be unrelated was given regarding giving in God's organization.
One CO found out that a certain congregatoin was not reading the accounts report once a month as scheduled by the WTS in the KM. The elders got read the riot act on that. The accounts servant was told to increase his volume when he accounced that there was a deficit.
Some congregations post their accounts report on the information board. Others would never do it even if Armageddon would come sooner.
Usually what I have seen is that the elders see what the deficit is and cover it themselves if the congregation doesn't come through.
(BTW the WTS frowns on using the worldwide money to make the KH mortgage.)
Blondie