You don't even have to be in the same country as your target. You can ship with a fake source and be pretty much invisible.
Using repurposed used hardware, this can also be crazy cheap.
Fun idea: buy junk vendor swag (stuffed animal, glass globe, etc) off of ebay in bulk, then mail it to people you know have recently left the company (say, from scanning LinkedIn). They'll probably keep the package around for a while before disposing of it. Or even better, someone else claims it as 'free swag,' and keeps it in the office.
Extra points: make it something powered (like a clock) and make them plug it in. Battery charge for initial scan, and if you get lucky, they'll recharge the battery by plugging in the device.
Using repurposed used hardware, this can also be crazy cheap.
Fun idea: buy junk vendor swag (stuffed animal, glass globe, etc) off of ebay in bulk, then mail it to people you know have recently left the company (say, from scanning LinkedIn). They'll probably keep the package around for a while before disposing of it. Or even better, someone else claims it as 'free swag,' and keeps it in the office.
Maybe it'll stay in there a long time: https://en.wikipedia.org/wiki/The_Thing_(listening_device)
Extra points: make it something powered (like a clock) and make them plug it in. Battery charge for initial scan, and if you get lucky, they'll recharge the battery by plugging in the device.