[ARCHIVE ANSWER]
If the find no drugs, they will seize your money if it's a large amount. For one, if they have a search warrant for your house it is quite likely they have sufficiently tied drug sales or use to your residence enough to allow them to seize money.
Secondly, even if they end up wrongly seizing your money they will face no penalty. You will have to fight to get it back and they get to collect interest on it in the meantime, so they have no incentive to not seize it.