In addition to the Matthew that 'Pennines' has quoted, there is another Matthew Wignall that has service papers on Find My Past. This one enlisted on 27/2/1908 (should read 27/2/1903 - incorrectly transcribed on FindMyPast) giving his age as 18 years 3 months. His residence is given as 3 Brown Square, Preston. His parents are recorded as Matthew and Margaret. His height is almost the same on both records, the colour of his eyes and hair are exactly the same on both records.
It is possible that his parents tracked him down when he enlisted in 1902 and as he had joined without their permission he would have been returned to his parents.