Electroblade

Crackling lighting spreads from the hand of the caster to envelop the weapon being held in it. This lighting does not harm its caster. A creature touched by a weapon coated by the lighting will take 1d4 lighting damage. You have advantage on the attack roll if the target is wearing armor made of metal.

The lighting ignites flammable objects which touch the blade that aren't being worn or carried.

At higher levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 1d4 for each slot level above 1st.