[SpikeDmax]

Just replaced mine yesterday due to erratic needle movement. Fixed the problem.

You'll want from Amazon:
Lisle 13250 Oil Pressure Switch Socket - -$8
Standard Motor Products PS-230 Oil Pressure Switch - -$21 (non-prime item and took over a week to receive in the mail)

Remove yours (unclip wire first) and try some teflon tape on the threads to see if it stops leaking but it may be coming from the unit, not the threads. Get the Lisle socket and save yourself some grief.