I'm not quite sure what you are tracing. The etymology of the name GEISELHEART? That of the (sur)name Wrightson? Or your roots? Or someone else's?
In case you want to know more about the origin of the name GEISELHEART: I haven't come across this form. GEISEL looks German to me, I don't know about Norwegian, you'll have to ask someone like Satu. HEART appears to be English, not German; maybe it's something else. The combination is interesting.
Unlike on this site (and most books I've seen) it seems like the GEISEL/GISEL part does not mean "pledge", but is taken from the Germanic root GISA/GISLA meaning "spear". The two may be related though.
HEART obviously is the element HARDU ("strong, brave") and has nothing to do with the English „heart“.
If you are interested in more details about GEISEL/GISEL, let me know, I can provide further information.