Modelling a "scope probes' acting as an antenna" phenomenon in a circuit
The scope probe should be modeled as a lossy transmission line with the resistor/capacitor divider (10x probe is assumed).

The ground lead inductance should be added and you may couple this inductor to the inductance of your AC power wiring (50 Hz) [C2 in the image below]. 

You may also add capacitive coupling for same said AC power wiring (50 Hz) [L2 in the image below].

Forgive my poor and lazy image editing skills, your model may look similar to the attached image.

Note the added parasitic capacitance (C2) and indutctive coupling (between L2 and the ground clip) form the AC power line.



Please read Doug Ford's: "The sectet world of oscilloscope probes" founrd in the following link, which is also the source for the image attached, for the model's detail.