Double image produced on printed pages

[PTF2]

All prints have a ghost second image behind the first which is displaced downward.

Double image on printing

[Valsimot]

Measure the distance between the original and ghost image in mm and post here.

[PTF2]

Distance between images is 58 mm

[Valsimot]

The 56,5 mm is the fuser, there is no printer part that leaves 58mm repetitive defects.

The fuser is probably not heating enough to fix the toner to the paper, making it leave a ghost image after 56,5mm ( circumference of fuser roller).
If the printer is printing on a different type of paper, and it's not properly set in the driver that can be causing ghosting too, but it's very likely that the fuser went bad.
What paper are you using plain or something different? 

[PTF2]

Using plain paper. The printer gives an intermittent 50:2 error message on start up which disappears if you power down and then turn on.

is it easy to source and fit a fuse? What might this cost?

[Valsimot]

Look it up on eBay if you want to get it cheap, it's not hard to replace if you have skills with tools.

[PTF2]

Only one on EBay at a cost of £220! Given that the fuses is a serviceable part and often changed the price seems high and I wonder whether it is worth repairing at this cost?

[Valsimot]

If you have full toners or new toners in stock then it might be wort repairing, in other cases, it's too expensive.