TL;DR - Without dumping a bunch of money, is there a quick MacGuyver-y way to help diagnose what's causing the EMI in my house?
I have the curse that I'm a little too technical to be helped here by dummies.com, but not sophisticated enough to have or use the tools I imagine most of you would recommend.
Several times per day - sometimes hours without issue, sometimes firing once every 5 seconds - the wifi blips for a few seconds. I've caught command line ping dropping packets for about 2-5 seconds, on computers throughout the house. Notably, we realized the baby monitor also cuts out for just a few seconds at the exact same time ping goes down.
So it would appear my house is regularly awash in brief bursts of EMI, that's causing connectivity issues (especially a problem with video conferencing in the current covid-19 lockdown world). But I have no idea what to buy or rent to help me triangulate where this is coming from or what it could be. I have some dim memory that magic things can be managed with an oscilloscope and simple length of metal plugged into it operating as an antenna.
How can I find EMI?
(Meta - if there's a better place besides electronics.stackexchange.com for this please leave a comment)
UPDATE (for more information, as requested in comments)
The Baby monitor and its receiver is an Infant Optics DXR-8, audio and video over 2.4ghz wireless (NOT wifi / tcp-ip, but some point-to-point proprietary). In fact, shielded twisted pair cat5 appears undisrupted (but not a fix for everything getting disrupted in our wifi world). The wifi is 5ghz AC + 2.4 ghz N (both ranges/protocols impacted). To my knowledge, I'm not particularly close to any unusual EM sources - e.g. airport, military base, transformers - though I guess you never truly know. It is relatively dense population (single family residences every 35 feet) - I'm wondering if a neighbor has one of these "weaponized" routers that disables other people's wifi, but need some kind of proof before I go pounding on doors. All of this aside, to keep the question within format for stackexchange, assume generic American residential suburbia, and let's see if we can dream up a gimmick that works generally. Anything further peculiar to my immediate situation I can answer in comments.