When prep teacher Kerry Ford returned to her Brunswick home from a holiday on Monday, what she found behind her carport made her angry and upset.

Seventeen addressed and unopened same-sex marriage postal vote envelopes had been dumped in front of her children's cubby house.

The letters were addressed to houses in the surrounding streets.

"I think it happened last week, some of them have been eaten by snails," she said. "Our postal votes have also been stolen."