This appears to be **induced current** — meaning it’s **wirelessly transferred energy**

This appears to be **induced current** — meaning it’s **wirelessly transferred energy**, likely due to **magnetic coupling** from security systems operating at low frequencies (e.g., 125 kHz or 13.56 MHz).

This is **not the same as wireless cellphone charging**, but it shares a common mechanism: **electromagnetic induction**.

However, unlike consumer wireless chargers (which are shielded and regulated), many **retail security gates** are **poorly designed**, allowing **leakage fields** to generate **perceptible voltages** on nearby surfaces — including metal door frames, kiosks, and even clothing racks.