If I have a section 8 Voucher and I don't find a home can I lose my voucher?

In short, yes, you can lose your voucher. Normally you are given 60 days from the date of issue to find a home. If you can't find a home you could ask for an extension for one month at a time, but for no more than two months. This makes it a total of 120 days to find a home.