One hand in the sink and one hand on the stove, I feel a tingle. How dangerous and how to fix? (Not my home)
The house is not a potential death trap at every water fixture. The house is a potential death trap at the stove. 

Improving the grounding of the pipes is worse than useless. The only thing to do to keep your friend alive is to immediately stop using the stove and unplug it until it can be made safe to use, or replaced altogether. 

A qualified electrician or appliance repairman may be able to repair it or properly ground it, but the labor cost may exceed that of a new stove.