A strange property of lcd display?

[NullAndVoid]

So I was messing around with those lcd displays that come out of cheap calculators, radios etc. when I put the pins in contact with my desk lamp, the digits on the display would be visible. The lamp that sits on my desk gets rather hot so I thought  that had to do with it, but I kept messing around and found out the display would only be 'powered' when the lamp was on.

So I created the following setup:
**See attachment**

The red wire is connected to the metal shell of lamp and one end of the black wire is connected to the display, the other end is not connected to anything but without the black wire connected to the display ,it wont show any digits. (the reason its showing random things is that there is no micro controller to drive it)

I came up with the following assumption as to why this is happening:

When the lamp is powered on, it creates some sort of electrostatic charge, causing the display to be powered but I am obviously not 100% sure.

So, why does the display act this way?

P.S: Was not 100% sure what section to put this in so I put it here.

[MK14]

LCD's of (that/similar) type, only need a relatively low, voltage of about a volt or so to drive them (light the segments). At virtually zero current (which is why watches/clocks can drive similar LCD's for a year or even 10, before needing replacement of the (around 1.5V to 3V or so) often tiny, battery(s) ).
Long leads, near electrical mains items, such as your lamp, can easily create (pick up) stray electric fields. Hence the LCD effects you have seen.

[VK5RC]

See what capacitor will conduct it and what inductor will block it? Is it mains frequency or switch mode spikes?

[ataradov]

You can enable segments by simply touching them with a length of wire (just a single wire). I did that many times. LCDs are just that awesome

But note that LCDs are very critical to DC voltages. Applying DC voltage will drastically reduce the life of the LCD.