Locating switches and crossings in railway networks

Imagine I have downloaded all ways with railway=rail of a country. Now I would like to select all nodes that should contain railway=switch or railway=railway_crossing. The list of situations is:

1. three ways end in one node
2. four ways end in one node
3. one node is in the middle of one way and at the start of another way
4. one node is in the middle of two ways

My search queries for cases one and two are:

1. ways:3- type:node
2. ways:4- type:node

My question to you: how can I select case three and case four?