On page 2-13 of the 1990 Funhouse Manual, it shows the Outhole Kicker Assembly. It looks like the coil stop (Part Number A-8038) has come loose. You need it and (2) #6-32 x 3/16 machine screws to reinstall it.
Attached is a picture of the assembly installed. Note the orientation of the coil wires. They must go towards the upper playfield, or they might make contact with the apron and short out.