Discussion on geysers etc. reminds me that, as a child in Scotland, I used to go out at Hallowe'en as a "guiser", i..e. dressed in scary clothing (e.g. as a witch or similar). Pronounced as in disguise. Little groups of us would go round to neighbours and, if lucky, would receive small gifts for some short recitation or performance. Similar, I understand, in Northern Ireland. It still happens but nowadays children usually have to be accompanied by responsible adults.