Oscilloscope On 2 Wire House Electric

[mentaldemise]

Hi. I just got an oscilloscope today, the wife thanks you Dave! 

I'm in the US, so 120V @ 60Hz mains. My house has old Knob And Tube wiring; 2 Wire with no ground. I seem to be getting feedback on the scope as when I don't have the probes hooked up to anything, there appears to be a tiny 60hz signal. 90mV peak to peak. Is this something I should be concerned about? I didn't have much luck searching things like "Run scope without ground" outside of things like isolation transformers which are way above my head right now.

Sorry in advance if this is not a good question. I just don't wanna blow anything up or burn the house down!

Thanks

(edit: added a picture)

[tggzzz]

Hi. I just got an oscilloscope today, the wife thanks you Dave! 

I'm in the US, so 120V @ 60Hz mains. My house has old Knob And Tube wiring; 2 Wire with no ground. I seem to be getting feedback on the scope as when I don't have the probes hooked up to anything, there appears to be a tiny 60hz signal. 90mV peak to peak. Is this something I should be concerned about? I didn't have much luck searching things like "Run scope without ground" outside of things like isolation transformers which are way above my head right now.

Sorry in advance if this is not a good question. I just don't wanna blow anything up or burn the house down!

Thanks

(edit: added a picture)

I know nothing about the US wiring codes, but personally I'd be worried about not having a ground. And that's whether or not I had a scope!

[tautech]

Hi. I just got an oscilloscope today, the wife thanks you Dave! 

I'm in the US, so 120V @ 60Hz mains. My house has old Knob And Tube wiring; 2 Wire with no ground. I seem to be getting feedback on the scope as when I don't have the probes hooked up to anything, there appears to be a tiny 60hz signal. 90mV peak to peak. Is this something I should be concerned about? I didn't have much luck searching things like "Run scope without ground" outside of things like isolation transformers which are way above my head right now.

Sorry in advance if this is not a good question. I just don't wanna blow anything up or burn the house down!

Thanks

(edit: added a picture)

I'd say with the probes attached to the scoe they are acting like an antenna picking up mains from your environment.
This behaviour is normal, in fact you can use this behaviour like a "near field probe" that is with no physical connection to the DUT.
Hold the probe close to a SMPS and you'll see a similar induced result but at a much higher frequency.

[mtdoc]

Picking up 60Hz noise without the probes connected to anything is normal.

Home wiring without a ground is another issue - and not safe - especially if you are going to be doing electronics work.

[Paul Price]

Having grounds can be just as dangerous as not.

https://www.eevblog.com/forum/beginners/new-lab-no-grounded-outlets/45/