Any device with a wifi antenna could do such a scan, provided it has the right software. I'm not exactly a tech expert but I do have aps like that from tech support home wifi and installing repeaters so I could get better signal in various parts of the house. If you're in an apartment, there may be many networks interfering, and use of software like that can be helpful in figuring out the best places for your wireless router/gateway, etc.

I don't think the OP is suggesting the use of packet sniffing software. We don't really care what data is being trafficked on the networks. We're simply looking for wifi networks on the voting machines themselves that shouldn't be there because they're not supposed to be wifi enabled.