For a large number of the QF 738 fleet the landing lights and the logo lights have been modified to have a pulse setting. The switches for these lights can be on full or pulse. The normal position for the logo light is not pulse however it is easy to mistakenly select the pulse position as there is only a small difference in position.
Also if there is a TCAS traffic alert lights will automatically pulse.
Unfortunately this doesn't seem to be inhibited on the ground in some aircraft. Meaning your landing lights can automatically pulse when taxiing and an aircraft appears as proximate traffic on TCAS.