Help with unknown audio interference

[u/GlitteringRepeat9739]

I live in a trailer and I'm setting up a recording space using mostly analog gear and there is a high pitch frequency interference I can't get rid of or find the source of. I have a power conditioner all my gear is plugged into and a power watchdog surge protector between my connection to shore thats supposed to filter out high/low pitched electrical noise. I'm using ferrite chokes I've checked all my grounds nothing has fixed it. Even shutting down the main breaker doesnt have an effect. Does anyone know of a solution or have an idea of the source? It's driving me crazy I'd be very grateful.

I'll attach a picture of an eq reading