Ballot stuffing is the illegal act of one person submitting multiple ballots during a vote in which only one ballot per person is permitted. The name originates from the earliest days of this practice in which people literally did stuff more than one ballot in a ballot box at the same time. In a government election, this is a form of electoral fraud.
Detecting ballot-stuffing depends a great deal on how good the record-keeping is. Most election systems match the number of persons showing up to vote with the number of ballots cast, and/or preparing the forms so that they are difficult to fake. A common method still used in small village elections throughout the USA uses two ballot boxes and a single sheet of paper for a ballot. After marking the ballot, the sheet is folded in half with each part dropped in the corresponding ballot box. The number of marked ballots in one box will equal the number of ballot sheet headers in the other ballot box, thus preventing ballot stuffing. In short, successful ballot-stuffing usually requires the misconduct of genuine registered voters and/or elections personnel.
Ballot stuffing with voting machines would be possible with Sequoia touchscreen machines. They have a yellow button on the back side which allows to vote again. Pressing the button also triggers two beeps so abusing this feature is essentially only possible without supervision. On other voting machines administrative access using a key or chip card might also allow a person to vote multiple times.
Ballot-stuffing can be accomplished in a number of ways. Often, a ballot-stuffer will cast votes on the behalf of people who did not show up to the polls (known as telegraphing); sometimes, votes will even be cast by those who are long dead or fictitious characters in TV shows, books, and movies (known as padding). In earlier societies with little paperwork, dead people were kept "alive" on paper for the purpose of ballot-stuffing. The family of the deceased often helped along, either to assist their party or for money.