Whatever it is, again please avoid from 'touch wood'. Cerita dulu-dulu. Now you know. Salib (cross). Dulu-dulu salib nya yang wood atu kan. So that's what it meant. Whenever bad things happen or when they pray to avoid bad things happened to them, they hold onto the wooden cross and pray to Christ. So that is what you called 'touch wood'.
We Muslims should not say or practise 'touch wood' or knocking on wood whenever we wish to avoid bad things from happening to us. Instead you should say Naa'uzzubillah. Get it. So if you used to practise it, AVOID IT.