Id ceramic disc capacitor
That is a 1.5nanofarad capacitor rated for 250 volts AC.  It is also a Y rated part.  The Y rating is a safety feature.

When you replace it, make sure to get a part that meets (or exceeds) the safety rating and the voltage rating.  Any Y rated part should meet the safety and voltage ratings.

The actual value is not as important.  It is for noise suppresion, as you suspected.  It won't matter if you get a 2nF part, or a 1nF, or the given 1.5nF.  Too small and it won't suppress noise effectively.  Too large and it will pass too much current and may cause problems.  Stay close to one or two nF.