Help Needed

[Guest treble charged]

A while back, the X button on my PS Dual Shock controller got "stuck".  I don't know how else to explain it, it just keeps pressing when it is plugged into the system.  I have tried taking it apart, as I thought that maybe a piece of plastic had broken off and was stuck against something in there, but no such luck.  If anyone call possibly help me, it would be very much appreciated.  Thanks.