I've picked up noise from a wifi modem before, only in some equipment though.
From: Doepfer_a100@yahoogroups.com on behalf of a11@live.nl [Doepfer_a100]
Sent: Monday, 13 June 2016 5:33 PM
To: Doepfer_a100@yahoogroups.com
Subject: [Doepfer_a100] Re: Loud ground loop hum
Sent: Monday, 13 June 2016 5:33 PM
To: Doepfer_a100@yahoogroups.com
Subject: [Doepfer_a100] Re: Loud ground loop hum
This is probably not precisely the case, but I thought to report this in here.
There was a time there was appearing a sort of signal sound, when I was playing my modular.
After some time I discovered that it was my internet modem. When I covered it with my hands, the sound disappeared.