I have a lump behind my ear lobe that is quite big. It is sore but I cannot squeeze anything out of it. I have tried bathing it with hot salt water but this does nothing. I think it is some sort of boil but how can I get rid of it.

I've had those too. Several times a day hold a warm washcloth over it for 15-min periods. If it doesn't break and drain soon by itself, you'll have to allow the doctor to deal with it.

I had one of these... let the doctor at it... I did a DIY job on mine and it lingered around for ages before clearing up.